[GadgetKen]

Will be in Bermuda next week (vacation) and will use my Digicel Bermuda and Maxroam sim cards. At least the Maxroam sim card WORKS and they do respond promptly to any questions I've had (unlike my Yackie, UM, UM+, Riing, and BuyTel sim cards or my Slingshot CDMA USB key; some of these might be resurrected in the future but I'm not holding my breath on it) but the dialout procedure is cumbersome on my Razr, and they still haven't assigned an incoming DID. Think I'll try to use up a chunk of the MaxRoam starter balance in Bermuda, and see if they fix the other issues in the future (if they do I'll add money to the card).
Since my travel is now mostly US (my AT&T or T-Mobile MVNO sim cards) or Caribbean and Bermuda(Digicel), an international callback sim card isn't as critical for me. The Digicel card works in multiple countries where they have networks and I have my Iridium phone if networks go down or I'm not near a tower. Plus I can always use a low tech calling card at a payphone...