Does it really need to be one application for two such completely different tasks? It's like asking for program for managing your finances, and try to crack WPA network with rainbow tables - all in one application. As for VoIP as in Video and Audio, I use Linphone on both windoze and GNU/Linux machines, without any problems.

For screen sharing, we have goddamn amount of solutions for that, VNC based or not. I don't see damn reason why it need to be bundled in one program, just to pretend being clone of Skype

See above.

Well, Linphone mentioned earlier doesn't have Maemo client, but SIP isn't some sh||tty proprietary dubious protocol, so you can call contacts with whatever other client you feel fancy... In fact, you can have three different clients for all machines, and it works all the same. BTW, SIP on N900 is supported since vanilla, including integration with addressbook, phone-ui, etc.

Subjective. I don't have any problems with using any SIP client that have a) dialpad b) addressbook c) decent setting allowing me to set up everything I may need (my SIP proxies, STUN server, etc), can't speak for others.

SIP is always peer-to-peer. BTW, this point *doesn't* apply to Skype, to be honest...

Good luck!

No - because Skype is, with high probability, a well-coded spyware. It was proven to send things like user's motherboard serial numbers to centralized server without informing about it, it is coded in a way that prevent checkign what it's really doing by *any* means (cleverly written, but that's hardly positive in that case) [1], and it's creator was already proven to include worst spyware in his programs (first kazaa). No surprise, that with Skype, it was ensured that no one will be able to determine what is happening inside.[1]

Also, because it is proven to be goddamned resource and network usage hog, by design (twice as much, if you happen to be marked as supernode by Skype, which of course, you don't have control over).

/Estel

[1] https://www.blackhat.com/presentatio...-biondi-up.pdf