[andy]

I got one recently, and took it abroad 2 weeks ago. It roams on any UK network, but chooses O2 for preference. Travelling through the countries ticex names plus Austria and Slovakia, I didn't try to register with every single network in every single country, but I didn't find any where it wouldn't.

I had read a comment here that it wasn't always reachable from O2, so I called it with my O2 phone several occasions in each country and it always rang. It's noticeable with both phones next to you that the caller hears about 3 rings before the other phone rings; this applies to calls in both directions. I made 3 calls home to UK from Slovakia Germany and France. A 10.2 minute call from France cost $2.11 + tax, about ?1.45 total.

The tariffs on the CallKey site are only available on secure pages, are quoted in dollars, and probably without VAT, as an initial balance of US $10.13 became $8.62 (= ?5). There are some errors on the 0044 site; typical call costs to landlines are in the range 20c to 25c. Mobile destinations are relatively expensive at around 60c, but I think I've found what could be a cheaper workaround. There is a cheaper rate of around 35c for calling UK 08 numbers and there are a wealth of especially 0871 callthrough numbers that could be used for many international mobiles, so this should save a typical 25c plus tax. I've called like this about 5 times, but not answered to see what the call quality was like - probably difficult to judge anyway with a phone to each ear and hearing your own voice

As ticex suggests, there may be cheaper callback possibilities with other providers, but some of these may be more tricky due to no caller ID at present. I suggested another possibility to someone here, and have two similar ideas - think about using callback and call diversion together. Or use web triggers, either on a PDA or via gprs ...?

Voipfone in fact has UK 0844 numbers on its tariff at 5p, and some of these can reach UK mobiles at the moment, but these are promotional offers; so for now it would be possible to use Voipfone with this SIM to call landlines for 9.6p, UK mobile for 13.5p, other mobiles for 18.5p per minute. They have some cheaper rates that are almost certainly tariff mistakes, but with certain other tariffs elsewhere it may be possible to make calls for about 4p per minute, or less. I really doubt if this would work though, but more playing about required.

It is rather odd that many companies count IoM mobile as a UK one without even knowing it, but other cheap call providers have no coverage there at all. From the UK, the cheapest way to call there has risen twice recently from 1p to 4p per minute; promotional price as I said, but maybe 18185's 5p weekdays, 2p weekends will last