[andy]

There are different versions of Skype, depending on the relationship between Skype and the network you are using.

On networks like 3, and I assume also the deal with Verizon (but I could be wrong for that part), the specific application there is using mainly callthrough on an access number which has been zero-tariffed by the network, plus a small amount of data for presence info, and this data is also free. As it is mainly an ordinary phone call, then it should even still work with only a 2g signal, such as the 2g roaming arrangements which the various 3 networks have for areas where their 3g signal is patchy or non-existent, e.g. 3 UK on Orange UK, 3 Ireland on Vodafone Ireland.

That is a customised version of a program called iSkoot, and there is also a general version, also based on callthrough, but then the access number is a call charged at the network's tariff, plus a bit of data I suppose. However, a brief search to check on this shows me that this was being shut down a couple of weeks ago. This closedown doesn't seem to affect the custom 3/Skype application, which is still working.

Skype also offers, or did offer but no longer seems to, its own similar program called Skype Lite, also based on callthrough access, or so it seemed from the description. That seemed to available for a fairly wide range of phones

In addition, Skype offers an arrangement called Skype To Go, which seems to be creating a different number to call for each contact, so that number will again be charged at the mobile network's tariff.

But what is being looked for in the context of this thread is a Skype application which uses only 3g data to make the call, on top of course of using wi-fi when available. I believe that when I looked at this a while ago, there was some ambiguity about which phones it could be used with, as it didn't seem to be ubiquitous.

I installed it on an E51 a year or two ago, but it didn't seem to be in offer for all Symbian phones at that time. I have scarcely used it, so certainly can't be counted an expert. In addition, for a while, Fring and Nimbuzz clients could be used with Skype accounts, which would have helped for phones where no Skype client was in offer, but these agreements have been ended, with stated reasons which seem to imply differences of opinion or interest between the companies.

Given that things seem to be changing every few months, and it was fairly difficult to find some of these things anyway - I can remember ambiguities between what 3 and Skype were saying, and links from one's website to the other and a dead page at the other end (or different 3/Skype versions on different phones handling for instance caller ID differently) - it's no wonder it's a bit tricky to keep up with what is going on with all of this ......... so maybe SIP is easier.