You say it seems memmory hung in INQ? Which version can you download on an INQ phone? Including VOIP functionality?

Yes you can download it without phonenumber.
With your mobile browser go to: http://fring.com 

Can't download without providing a phone number? That's lame.

With fring on my E65, it has all but replaced the home phone handset for me, skype and SIP support combined with the "my key" being re-defined as fring launch, means fring is a lot less crash prone, however as you say, high memory usage and (at least with Wlan) short battery time make it a little less than perfect.

Btw, thanks for the firefox3b2 support in comments :)

I see a huge listing of support for Windows Mobile and some other SMartphones, but a Skype ability on the Blackberry would be excellent