USBasp
The USBasp is easily available on eBay very cheaply. From China it's currently around available for £1.23 including postage. I got mine from Happy Buddha Trading for £3.45 as I was in a hurry - it was dispatched very quickly.
You must get one with a "JP3" jumper as you need to connect that to program the ATtiny85 (it puts the programmer in a slower mode). If you only want to program ATtiny85s then you can solder a wire over JP3 otherwise you could solder on a proper link like JP1
USBasp from Happy Buddha Trading (made in China)
