It would be great to have Linux Smartphone. But, who's network would I use?
Is it possible to put a wifi device driver on a microcard and secretly have work on a Windows or Palm based machine? Can you use VoIP on a Smartphone?

Thanks

Linux smartphones use any network they are configured for - just the same as any smartphone (or, indeed, any phone). You won't actually notice much difference at the UI.
http://www.cellular-news.com/story/28971.php
http://www.geekzone.co.nz/content.asp?contentid=5854
http://hardware.slashdot.org/article.../05/04/2235209

Note: last I heard, PalmOS was linux.
http://www.palminfocenter.com/news/9...bile-platform/
http://www.fiercedeveloper.com/story...utm_source=rss

There are linux voip phones - so, yes you can. Ideally you use a sip account.
http://www.linuxdevices.com/news/NS6190886481.html
http://www.phonearena.com/htmls/Linu...le-a_1363.html

Some phones are very configurable.
http://www.informationweek.com/news/...leID=206101269
http://www.geekzone.co.nz/content.asp?contentid=6554

One of the advantage of embedded linux for phone vendors is the ease with which additional functionality can be added... combine with controll of the OS by the supplier and there is real competitive potential there.