I have a Dell Latitude CP laptop that I've used for 2 years as an imaging platform. It's configured for imaging and telescope control:
P166 MMX processor, touch-pad, Win98
Koss microphone/earpiece (for Digital Sky Voice, etc)
Dell combo PCMCIA card, 33.6 modem and 10B-T lan
Socket serial I/O card, PCMCIA
I have successfully controlled a Meade LX-200, Tak FS-102, ST-4, ST-4x, ST-7 with this setup. With the extra serial port you can use the modem, the built-in com port (telescope control) and the serial card for a imager like the ST-4. Laptop works great, battery is in good shape and touch pad works fine. All in all, this is a good, durable laptop.
Asking $250 or will trade for a Canon EF/USM lens or an IBM microdisk.