LG Optimus GT540.
Free on Pay Monthly
£59.99 on Pay & Go
3 Megapixel camera
2GB memory card included
I have ordered one of these since they recently came down in price from £79.99 to £59.99.
This is an ONLINE ONLY deal that I am aware of. I checked the o2 shops and they didn't have one for this price.
I think you may also be able to get cashback through Quidco but I haven't used it myself.