Thanks, and sorry I haven't been here for a while.
You might consider callback services as well as calling cards, and perhaps have both available.
For calling cards, it depends slightly if you are thinking of landlines or mobiles. Some mobile networks have free 0800 and equivalent numbers, but some are blocked. I don't myself have a calling card that covers all those countries, but you could look at
www.universalcaller.com or
www.enjoyprepaid.comsome of their numbers are blocked in some countries though. Both are affiliates or somehow part of Nobelcom.
There are some other American ones that I need to remember where to look, and I'll try and come back with more. The Americans tend to have higher rates for some of these Eastern European countries.
Overall though I think a callback service is better. You call a trigger number, then hang up. Then you are called back with a ringing tone and dial the required number. Typical costs are very similar to cheap calls operators prices in the other direction.
Get a local SIM card in an unlocked mobile, and call cost for those countries to UK landline can be in the US 26c to 28c range. From landlines rates from 21c to 7c
I would recommend
www.callbackworld.com www.enlinea.com Both seem to be resellers of the same service, though Enlinea has cheaper rates in some cases, including some of those I think (I looked up Czech Rep the other day for someone). You have an account post-paid by credit card, and can have more than one number on the account, including landlines (like hotel room) for cheaper rates of course.
I also have a Riiing SIM which has calls to UK for €0.39 per minute + €0.25 connect, and free incoming calls in about 70 countries including all of those. It has a Liechtenstein number.
www.riiing.comRiiing use its own callback system anyway, but it has been possible but a bit flaky recently to use it together with Enlinea or CBW with double callback and call costs of US 12c or 14c. ** Right now I would not rely on this as the only choice, but maybe use that and a local SIM and local landlines too. I also have routing number for incoming calls with Enlinea (and a UK 0844 that goes to it).
** Edit - it would appear that Enlinea tariffs for Liechtenstein mobile have increased. One service is now 43c but another is 21c. I've got an eye on CBW ... **
I hope this is a useful start, but may have too much confusing detail, and need editing when I'm more awake, so ask for more info where required.