Mains adaptor for EOS 500D (ACK-E5)

[Swatcher]

I need a mains adaptor but the Canon price is a bit steep. I notice there are some budget ones on Amazon but I hesitate to dive in without asking around first. Has anyone used non-Canon adaptors or have any knowledge of these manufacturers and would care to comment?

http://www.amazon.co.uk/s?ie=UTF8&field-keywords=ack-e5

Cheers,
S