I Have set myself up with the HP deskjet 450 WBT, it has the battery and a bluetooth card that fits in its compact flash slot in the back. I'm using an ibook 1Ghz, w/ bluetooth (obviously) and extra ram ( 640). I needed to be portable and was very dissapointed at first that there are very few portable printer options on the market. I am using this setup to allow me to invoice customers on the spot when I have to do work at there home (i am a heating contractor so this is daily).I chose the HP, for a few reasons, i am fond of having a totally wireless set up (BT mouse too) because it is clean to set up anywhere on any avail. surface, even several tables chairs etc. that aren't beside each other. also the HP uses less $ in ink, ( i seem to remember it prints more per cartridge$).
Do I like my Printer? Its a bit slow... but it does print nicely, good colour, clean never any blemishes or lines, the battery life is outstanding for such an unassuming battery( it is also very good at giving advance warning that it may need a charge) ink lasts reasonably long, I'm on my 3rd cartridge in 6 months. the bluetooth interface is just plain cool( however i was somthing pissed because Apple didn't support BT printers till about march and i bought mine in jan.) the other detractor is its size i guess, when I was shopping I would have expected portables to be smaller, but it fits nicely into my laptop bag so really it has never been an issue since i bought it. Also it is quite tough, mine gets kicked and scratched around alot and has never hesitated to spit out an invoice yet.
-Kevin in Canada