One question about 0044 product: on their site they write the billing is done at 6 seconds increments, and not the usual 60/60 like almost all the other providers (including the other IoM based ones). Can you confirm that?

Geodesa is not 60/60 either:

http://www.globalsimcard.co.uk/moreinfo.htm

Billing / Help:

? 30 Second minimum billing, 6 seconds thereafter
? No surcharges, no minimums and no connect fees

Yes. 30/06 as Przemolog says, same for all versions I would think. But you say some IoM based ones are 60s units - Callblue maybe?

I can confirm, what Przemolog and Andy already confirmed. Geodesa and 0044.co.uk shold be 30/6 billing. GT-SIM prepaid 60/60.

According to their websites, 60/60 are: gt-sim, Callblue and Talafone.
AFAIR Globalsim Holiday/Business from Globalsim.net was also announced to be 60/60.

The CallKey SIM also allows you to have voicemail that is accessable from the website as well as sent by email and also notified by SMS at the same time. You can also forward calls to pretty much any other number for free and, if that number does not answer the CallKey voicemail kicks in - some interesting options to play with.

Caller ID is promised as an option in the future

On the CallKeyOne SIM, if a call is not hung up immediately try using '##' to force hangup. The lack of hangup is related to poor signalling from the carriers. The closedown of the call by itself if done by silence detection which should backdate the billing to the first point it first heard nothing - if that makes sense ;)

Aha, thanks - I shall try this soon

Let's be clear - I didn't have this hang-up problem at all with the CallKey phone on its own, so I have no complaint against them at all.

It was only when used with a different callback, and then did not occur after callback was used to the forwarded O2 phone received on the IoM number. I'll mess about with it a bit later on; it would be good if it works, as if they later introduce caller ID, then less need for O2 as well to have the range of callback methods or protect this hang-up issue.
_

Also worth bearing in mind that the CallKey SIM is not primarily SMS triggered but USSD. The manual string for dialling a number using USSD is *125*1*+{Int Format number}# this also works for the various shortcodes. This helps in Nokia handsets that have problems doing this by themselves.

Should this fail then the system should fail over to SMS automatically but the manual send string (should you be interested) is *1*+{Int Format Number}# which is sent to one of a number of SMS access points. This is useful in places like the UAE where USSD is blocked in a way that fools the automated retry.

I have just noticed that telestial is selling another globals sim with a UK number. It seems to be callkey ... but not quite. They call it the AMBASSADOR

Anyone know if there is a new Global sim card on the market?

http://www.telestial.com/sim_cards.php