mig33 has one million users across 200 countries

Link: mig33 Delivers Mobile VOIP to One Million Users – from Manchester, to Melbourne to The Maldives.

mig33, a mobile VOIP service, is delivering more than one million users with cheaper calls and a range of communication tools including chat, SMS and instant messaging.

Depending on the country, users can save up to 95% on their international calls and roaming costs by using mig33 to create a call between any two phones. The benefit of mig33 is in combining a mobile instant messenger and an inbuilt international calling card. But the difference with mig33 is it is one easy-to-use service customers install on their phone. Customers receive reduced call costs without the inconvenience of having to punch in serial numbers like prepaid mobile phone cards.

Well they’re definitely a player. I only heard about them and downloaded their applet yesterday!