http://www.writetothem.com/ - for a complete list of contacts and which will fax or email your representative.
http://www.hearfromyourmp.com/ which aims to have you develope a longer term relationship with your MP - by putting you in touch with your MP. "Not for a specific purpose, but in order to hear what they're working on, to debate their thoughts in a safe, friendly environment, and generally to build better, more useful relationships between constituents and their MPs."
http://www.theyworkforyou.com/ - voting records for your MP