1 M. A. Nowak, J. B. Plotkin, and C. Krakauer, J. Theor. Biol. 200, 147 1999 .

2 M. A. Nowak and N. L. Komarova, Science 291, 114 2001 .

3 F. A. Matsen and M. A. Nowak, Proc. Natl. Acad. Sci. U.S.A. 101, 18053 2004 .

4 C. Castellano, V. Loreto, A. Barrat, F. Cecconi, and D. Parisi, Phys. Rev. E 71, 066107 2005 .

5 E. Ben-Naim, Europhys. Lett. 69, 671 2005 .

6 G. Deffuant, D. Neau, F. Amblard, and G. Weisbuch, Adv. Complex Syst. 3, 87 2000 .

7 S. N. Durlauf, Proc. Natl. Acad. Sci. U.S.A. 96, 10582 1999 .

8 P. L. Krapivsky and S. Redner, Phys. Rev. Lett. 90, 238701 2003 .

9 K. Sznajd-Weron and J. Sznajd, Int. J. Mod. Phys. C 11, 1157 2000 .

10 B. Kozma and A. Barrat, Phys. Rev. E 77, 016102 2008 .

11 I. J. Benczik, S. Z. Benczik, B. Schmitmann, and R. K. P. Zia, e-print arXiv:0709.4042; Europhys. Lett. to be published .

12 T. Antal, P. L. Krapivsky, and S. Redner, Phys. Rev. E 72, 036121 2005 .

13 Y. Lee, T. C. Collier, C. E. Taylor, and E. E. Stabler, in Proceedings of the Tenth International Symposium on Artificial Life and Robotics Beppu, Japan, 2005 .

14 T. C. Collier and C. E. Taylor, J. Parallel Distrib. Comput. 64,

15 L. Steels, Evol. Commun. 1, 1 1997 .

16 S. Kirby, Artif. Life 8, 185 2002 .

17 L. Steels, Auton. Agents Multi-Agent Syst. 1, 169 1998 .

18 L. Steels, Artif. Life 2, 319 1995 .

19 L. Steels and A. McIntyre, Adv. Complex Syst. 1, 301 1999 .

20 A. Baronchelli, M. Felici, E. Caglioti, V. Loreto, and L. Steels, J. Stat. Mech.: Theory Exp. 2006 P06014.

21 A. Baronchelli, L. Dall'Asta, A. Barrat, and V. Loreto, in Artificial Life X: Proceedings of the Tenth International Conference on the Simulation and Synthesis of Living Systems, edited by L. M. Rocha, L. S. Yaeger, M. A. Bedau, D. Floreano, R. L. Goldstone, and A. Vespignani MIT Press, Cambridge, MA, 2006 pp. 480-485; e-print arXiv:physics/0511201.

22 A. Baronchelli, L. Dall'Asta, A. Barrat, and V. Loreto, Phys. Rev. E 73, 015102 R 2006 .

23 L. Dall'Asta, A. Baronchelli, A. Barrat, and V. Loreto, Europhys. Lett. 73, 969 2006 .

24 L. Dall'Asta, A. Baronchelli, A. Barrat, and V. Loreto, Phys. Rev. E 74, 036105 2006 .

25 A. Baronchelli, V. Loreto, L. Dall'Asta, and A. Barrat, in Proceedings of the Sixth International Conference on the Evolution of Language, edited by A. Cangelosi, A. D. M. Smith, and K. Smith World Scientific, Singapore, 2006 , pp. 11-18.

26 B. DeCleene, L. Dondeti, S. Griffin, T. Hardjono, D. Kiwior, J. Kurose, D. Towsley, S. Vasudevan, and C. Zhang, Proceedings of Military Communications Conference (MILCOM 2001) IEEE, Piscataway, NJ, 2001 , Vol. 1, pp. 113-117.

27 D. Angluin, in Proceedings of the 12th ACM Symposium on Theory of Computing ACM, New York, NY, 1980 , pp. 82- 93.

28 D. S. Hirschberg and J. B. Sinclair, Commun. ACM 23, 627 1980 .

29 G. LeLann, IFIP Congress Proceedings North Holland, Amsterdam, 1977 , pp. 155-160.

30 N. Malpani, J. Welch, and N. Vaidya, Proceedings of the Fourth International Workshop on Discrete Algorithms and Methods for Mobile Computing and Communications ACM, New York, NY, 2000 , pp. 96-103.

31 S. Vasudevan, B. DeCleene, N. Immerman, J. Kurose, and D. Towsley, Proceedings of the Third DARPA Information Survivability Conference and Exposition (DISCEX- III) IEEE Computer Society, Washington, DC, 2003 , Vol. 1, pp. 261-272.

32 Q. Lu, G. Korniss, and B. K. Szymanski, Proceedings of the 2006 American Association for Artificial Intelligence Fall Symposium Series, Interaction and Emergent Phenomena in Societies of Agents AAAI Press, Menlo Park, CA, 2006 , pp. 148-155.

33 D. J. Watts and S. H. Strogatz, Nature London 393, 440 1998 .

34 B.-Y. Lin, J. Ren, H.-J. Yang, and B. H. Wang, e-print arXiv:physics/0607001.

35 Note that on strongly heterogeneous scale-free graphs the order, whether the listener or the speaker is picked first, strongly impacts the efficiency toward global agreement. Picking the listener first at random will increase the chance for picking a node as a neighbor with larger degree for speaker. In turn, hubs will be the most frequent speakers, giving rise to faster convergence to global agreement at a mildly elevated memory cost 24,25 .

36 R. Meester and R. Roy, Continuum Percolation Cambridge University Press, Cambridge, England, 1996 .

37 M. Penrose, Random Geometric Graphs Oxford University Press, New York, 2003 .

38 J. Dall and M. Christensen, Phys. Rev. E 66, 016121 2002 .

39 P. Gupta and P. K. Kumar, IEEE Trans. Inf. Theory IT-46, 388 2000 .

40 F. Xue and P. R. Kumar, Wireless Networks 10, 169 2004 .

41 B. Krishnamachar, S. B. Wicker, and R. Béjar, Proceedings of Symposium on Ad-Hoc Wireless Networks IEEE Globecom, San Antonio, Texas, 2001 , Vol. 5, pp. 25-29.

42 W. Krause, I. Glauche, R. Sollacher, and M. Greiner, Physica A 338, 633 2004 .

43 J. Branch, G. Chen, and B. K. Szymanski, Proceedings of the International Conference on Networking (ICN 2005), Lecture Notes in Computer Science Vol. 3420 Springer-Verlag, New York, 2005 , pp. 438-448.

44 M. E. J. Newman, SIAM Rev. 45, 167 2003 .

45 G. Korniss, M. A. Novotny, H. Guclu, Z. Toroczkai, and P. A. Rikvold, Science 299, 677 2003 .

46 Q. Lu, G. Korniss, and B. K. Szymanski, Proceedings of the Third International Conference on Networked Sensing Systems (INSS 2006) Transducer Research Foundation, San Diego, 2006 , pp. 164-171.

47 D. J. Watts, Am. J. Sociol. 105, 493 1999 .

48 G. Chen, J. Branch, and B. K. Szymanski, Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05)--Workshop 12 IEEE Computer Society, Washington, D.C., 2005 , p. 244.1.

49 B. K. Szymanski and G. Chen, The Computer Journal to be published .

50 A. Bray, Adv. Phys. 43, 357 1994 .

51 E. Ben-Naim, L. Frachebourg, and P. L. Krapivsky, Phys. Rev. E 53, 3078 1996 .

52 T. M. Liggett, Interacting Particle Systems Springer-Verlag, New York, 1985 .

53 J. A. Glazier, M. P. Anderson, and G. S. Grest, Philos. Mag. B 62, 615 1990 .

54 S. A. Safran, P. S. Sahni, and G. S. Grest, Phys. Rev. B 28, 2693 1983 .

55 P. S. Sahni, D. J. Srolovitz, G. S. Grest, M. P. Anderson, and S. A. Safran, Phys. Rev. B 28, 2705 1983 .

56 K. K. Kaski, J. Nieminen, and J. D. Gunton, Phys. Rev. B 31, 2998 1985 .

57 S. Kumar, J. D. Gunton, and K. K. Kaski, Phys. Rev. B 35, 8517 1987 .

58 C. Roland and M. Grant, Phys. Rev. B 41, 4663 1990 .

59 B. Derrida, C. Godrèche, and I. Yekutieli, Phys. Rev. A 44, 6241 1991 .

60 B. Derrida and R. Zeitak, Phys. Rev. E 54, 2513 1996 .

61 P. L. Krapivsky and E. Ben-Naim, Phys. Rev. E 56, 3788 1997 .

62 C. Sire and S. N. Majumdar, Phys. Rev. Lett. 74, 4321 1995 .

63 C. Sire and S. N. Majumdar, Phys. Rev. E 52, 244 1995 .

64 P. A. Alemany and D. ben Avraham, Phys. Lett. A 206, 18 1995 .

65 T. Masser and D. ben Avraham, Phys. Lett. A 275, 382 2000 .

66 M. Wykes, Q. Lu, G. Korniss, B. K. Szymanski, and Z. Rácz unpublished .

67 K. Tafa, S. Puri, and D. Kumar, Phys. Rev. E 63, 046115 2001 .

68 B. Kozma, M. B. Hastings, and G. Korniss, Phys. Rev. Lett. 95, 018701 2005 .

69 A. Helmy, IEEE Commun. Lett. 7, 490 2003 .

70 M. E. J. Newman and D. J. Watts, Phys. Lett. A 263, 341 1999 .

71 A. Barrat, e-print arXiv:cond-mat/9903323.

72 M. Barthélémy and Luis A. Nunes Amaral, Phys. Rev. Lett. 82, 3180 1999 ; Phys. Rev. Lett. 82, 5180 1999 E .

73 D. Boyer and O. Miramontes, Phys. Rev. E 67, 035102 R 2003 .

74 C. Castellano, D. Vilone, and A. Vespignani, Europhys. Lett. 63, 153 2003 .

75 Y. Yu, B. Danila, J. A. Marsh, and K. E. Bassler, Europhys. Lett. 79, 48004 2007 .