Young, Free and Single

If you're young, free and single, or even not all three of those, one of the most popular internet dating sites happens to be entirely free of charge. Have a look at:

http://www.plentyoffish.com/

Free Events in London

A bit London-centric this one, but Time Out online lets you search for all free events over the next week in London:

http://www.timeout.com/london/search.php?date=Next+7+days&free_event=1&search=2

This site also lists free events in London:

http://www.londonisfree.com/

Observer: Big Culture on a Small Budget

This article from the Observer has lots of suggestions on how to save money on going out:

http://www.guardian.co.uk/stage/2009/mar/01/saving-money-entertainment

Spotted by Locals

Spotted by Locals provides excellent free travel guides for cities all across Europe including London, written by local people.

http://www.spottedbylocals.com/