Hi, perhaps this is slightly OT, but I was wondering whether such an app could be used to send sms via commercial providers such as Vyke (http://www.vyke.com).

Vyke makes an app for Symbian phones allowing users to send sms through its servers directly from the normal sms interface on their mobile. They never released a version for N900, so in order to use it I now need to use their website on MicroB.