Wow! Thanks Evan! Your compilation and work is probably the best work on the entire PrepaidGSM.net forums!
A couple of things regarding my Q-card payg plan:
1) I went to the Wind store today and got my menus changed to english.
He called 1227 and spoke to Q customer support (and presumably asked them to change it to english.) Then he dialled 1224.
Dialling 1224 gives you an option to change the menus to english So now when I dial 1223 to add credit, or 1225 to check credit I can understand what is going on. Kinda handy. (Although the texts I receive from Q are still in Greek).
2) The €1 for 100MB that I wrote about last year (the one that seemed to offer unlimited data!) is reported to have ended several weeks ago. Around March 1st, my speeds suddenly went from 1M down/up to 50k down/up.

Very noticable! The data kept working and I wasn't getting charged for any data. Tolerable for gmail, Facebook, weather apps, etc... but pretty much unusable to check any webpages. Impossible to stream a YouTube video. And forget about tethering... lucky if after 5 minutes Gmail would come up in HTML mode...
So I bought some credit and texted "500MB" (no quotes) to 1210 today. (seems to also work the same as sending "500" to 1210), but 50k up/down issue (using speedtest.net) still the same. :-/
The Wind/Q store was closed by the time I realized this, but next time I'm in town, I will talk to him and see if I can get more information about this. Will update if anything changes, or if/when I figure out a solution.
Thanks again for the compilation update!