Just a quick reply:
HHM = available @
http://www.handheldmed.com
B = both palm and WinCE
Peds-specific stuff for PDA's (I'm sure there's more, but this is what I'm immediately aware of):
5 minute peds clinical consults - B - (HHM)
growthcharts - Palm -
www.statcoder.com
kidometer - Palm -
www.kidometer.com
General but helpful in peds:
redbook - B - (HHM)
physician's drug handbook - B - (HHM)
epocrates - Palm
qID - Palm
medscape - Palm
harrisons - B - (HHM)
merck - B - (HHM)
(basically, plan on buying the whole HHM library, 'cuz you won't regret it!)
re: no white coat (I'm married to a third-year peds resident, so I can help a little here):
You deal with the no-pocket issue by leaving your things in your staff room. You generally don't need your pockets full of books while in the patient's room and just leave them in the staff room. If you need equipment in the room (e.g. otoscope), you carry it with you or you have a set in the clinic room. Carrying a PDA allows you to carry drug books and other books with you while not having many pockets!
My wife uses a WinCE device in peds, is happy with it, and is reluctant to use Palms because of the differences between the devices. So, don't think that just 'cuz you're interested in peds you'll have to get a Palm.