Went out early to pick up another iMac G4 (15" but 1ghz so can be upgraded to 2gb RAM) I got for £15 on eBay. Turns out to work well but has an ugly cosmetic crack in the back of the dome, which is going to make it less valuable - it was described as a scratch but never mind, for that price I'm not too bothered.
Got that home, then went to two car boot sales - at the first I got an Apple Airport Express base station, an 85W Magsafe charger, a 13A plug and a UK plug to fit them, and two boxes of 10 sachets of washing machine descaling poweder (usual price around a tenner) for a total of £5 plus £1 entry. The magsafe works but the cable insulation is damaged near the plug, as is often the case. I think heat shrink ought to fix it. Haven't checked the Airport Express thing yet.
later - almost forgot because I left it in the hall, I also got an HP Jornada 545 pocket PC for a fiver, with accessories including the charging cradle etc. Looks to be working, it's just charging now.
At the second I got another lomography camera (a weird variant on the usual 4 frames on one action camera, with four very narrow vertical strips across one frame) for £2.50, and a rather nice Casio watch for £6 - this one isn't a radio-controlled waveceptor, but it shows tides, phases of the moon, and has a built in temperature sensor, I think I sold the last one for £15. Entry there was only 50p which was good, and I ran into youngest niece, who was selling costume jewelry etc., which was nice.
Just uprgraded the G4 to 2gb RAM, Wifi G, 120GB HD and a DL DVD writer, and I have some speakers for it, so that ought to make a reasonable profit too - won't be huge, but enough to make it more or less worthwhile. I'm installing Leopard now, we'll see how badly that goes.
All in all a reasonable day. But tomorrow I need to get out somewhere for a long walk, I need exercise!