I used the B-Mobile products twice, both times activated by Skype calls (i.e. land line from their point of view)
After you have reached an English speaking rep, you will be called back at your hotel or wherever to confirm that you exist. The card is immediately activated for 10 days.
An activation code can be snail-mailed to you for full activation beyond 10 days. This last time they asked if I needed it for more than 10 days. I said no, and the call ended at that point. Took all of 5 minutes and $0.3 in call charges.
If you need it for more than 10 days, you can arrange for the snail-mailing of the activation code, OR repeat the activation process again after 10 days.