Mac's are nice, but I'd go for a powerbook over an ibook.
Remember, with laptops, you definetly get what you pay for. stay away from no names. Some people like compaq's, some Dell's, some Toshiba's, and almost everyone loves IBM's..
The best list I've seen:
1)IBM
2)Toshiba
3)Dell
4)compaq
5)HP
(although the last two are the same now...)
Anyways my suggestion for a laptop is the
IBM X31
Technically this years model is the x40, but the major difference betwen them is the X31 has 16MB video ram, while the X40 shares.
It's ultralight weight, (about 1.6kg) and the battery life is around 4-4.5 hous (depending on usage, wireless, etc.)
It has no cdrom built in, but you can get an external one, or buy the ultrabase as well, which add's around 1.4kg, but includes an ultra bay (for cdrom type drive, extra hd, etc. plus space for an extra battery, bringing the battery life to 8-9 hours.
Should be around 1500US, note entirly sure, as I purchased mine here in Taiwan for 1200US (including targus carrying case, crappy optical mouse, and an external cdrw/dvd drive)
They are cheaper here however, and mine does have chinese characters on the keys as well as romanized characters)