[OTOTOT] accommodation in London

[viktoras d.]

I will be coming to the e-biosphere event 
(http://www.e-biosphere09.org/) May 30 - June 5.  Would appreciate if 
anyone could share experience on accommodation options in London (not 
too expensive, preferably, I'm taking my family). What to avoid, what to 
search for?..

Thanks in advance :-)
Viktoras