I’ve found the solution to my portable storage needs: an old (20Gb) laptop hard disk from my internal IT support department and a cheap (Â£2.99 + postage) USB enclosure picked up from eBay.co.uk. One of my clients bought something similar a few months back and it has taken me this long to get hold of a suitable hard disk; but now I have a decent amount of portable storage that I can format with NTFS (or any other file system I choose) and transfer between PCs at home and work.
The enclosure I bought is mostly aluminium, with a single LED to indicate power and/or drive access, and is just big enough for a slimline (9.5mm) laptop disk drive. It has a Y-shaped connector cable, with two USB 2.0 connectors at the forked end and a proprietary connection at the other, which is used to power the unit. I’ve found that I need to use both connectors to draw enough power on a Compaq or Dell laptop (The Compaq and IBM desktop PCs I tried seem to work with just one connection). Supplied with a driver CD (for Windows 98), screws, and a mock-leather wallet, I had no problems getting Windows XP to recognise it (without any additional software), and whilst the disk I was given only spins at 4200 RPM, it seems plenty fast enough for my needs.