There are some pegs on eBay.co.uk right now ->
http://cgi.ebay.co.uk/Foot-Pegs-90-0...item20b7bbb486
http://cgi.ebay.co.uk/MOTOCROSS-FOOT...item35aedfb9cc
http://cgi.ebay.co.uk/Moose-Racing-P...item41552de00b
http://cgi.ebay.com/ebaymotors/Yamah...Q5fAccessories
These sometimes bolt straight on, other times (like Uberthumper & myself) a small locating hole needs drilled in them for the spring.
I have these pegs on my TTR, and they are pretty good, well I've never slipped off them anyway. Don't expect quality but they are perfectly servicable and strong. You might need to treat them to a coat of paint once a year if you like to keep your bike nice and clean.
I also have Pivotpegz (on the Tenere), and they are realy good quality although do require servicing once a year as the name suggests they 'pivot' This makes them very comforatble for long periods of standing time as they allow the bike to move under your feet but you still keep realy good contact with te bike and get lots of feeling through them.
If I was choosing between the cheap pegs and the pivotpegz, for a bit of light trail riding lasting maybe a few hours a week, I'd go for the cheap ones. If I was spending long periods standing, then I'd opt for the Pivotpegz.
Both are great at what they do.