Is it possible to set up a bluetooth home user network? If so, which components do I have to buy. My current configuration is: 1 internet cable modem plugged on desktop , 2 desktops(Suse 10 and Mandrake 9) , 1 laptop (Suse 10) , 1 palm tungsten E2 and a house with many walls. Thanx in advance

Yes it's possible. The only components you need are bt dongles for each computer. Check the bluez page for packages to install & setup instructions.
Bluetooth can only connect up to 7 other devices (no problem in your case) but you can have more then one if needed.
The best dongles have CSR chips. Others work but often need small workarounds (my ISSC chips need to use a smaller MTU so the transfer rate is a bit slower ~70KB/s nearby). With walls, make sure to get Class I (100m) ones!

My setup has a dedicated box to route the 'net - The net comes in on ppp0 and the wired network uses eth0. I only use my laptop with BT (which is sometimes wired) so I keep the BT device separate on bnep0 (when it appears). As such, the BT network acts in the same way as the wired, with connections being masqueraded as they pass through the firewall.

But if you are having all your comps on one network it would be better to create an ethernet bridge. As each comp connects it may be given different devices bnep0..6 so the bridge would keep everthing together. As I said, more info is avail able via bluez.sf.net