These experiments were conducted in 2002. I'm pretty sure I've shot some better quality photos(with black background and more clear drop profile), but it seems I can not find them anymore. 
Anyway, I did these experiments because of this paper:
Y. Amarouchene, G. Cristobal, and H. Kellay, Phys. Rev. Lett. 87, 206104(2001)
Apparently I failed to achieve any further quantitative result, so I gave up. Last year(2005), a french group published another paper on this topic on Phys.Rev.Lett., which gives a more clear description of these non-coalescence phenomena. See:
Y. Couder, E. Fort, C.-H. Gautier, and A. Boudaoud, Phys. Rev. Lett. 94, 177801 (2005)