Mobile internet telephony firm Vyke said this week that it has extended its existing agreement with Finnish handset vendor Nokia to bring its VoIP application to more smartphones.

Vyke’s software package was initially made available for download in March last year in a select number of European markets. The extension to this deal will see the application made available to a large number of global markets and new wifi-enabled mobile devices in the Nokia E and N series.

Meanwhile, Skype’s own VoIP app has been made available on the Apple iPhone via the App Store, delivering free Skype-to-Skype calls over wifi and messaging connectivity over 3G.

The catch however, is that Apple’s terms and conditions for iPhone usage have long stated that users are not allowed to make VoIP calls over 3G. But an apparent bug in the forthcoming iPhone OS 3.0 firmware seems to make Skype calls over 3G possible, according to reports. It remains to be seen whether this ‘feature’ will be fixed before the commercial version of the software is available, but many users will undoubtedly be pleased by the discovery, as they will with reports that version 3.0 will also make tethering legitimately available on the device.