This is the list of free classified sites I came up with earlier in the month. If anyone has any to add to this list, or has tried any of them please add to this thread.
http://www.advertsdirect.com/classifieds/XcClassPro.asp
http://www.adoos.co.uk/
http://www.classifieds.co.uk/
http://www.vivastreet.co.uk/
http://www.adtrader.co.uk/postcode_splash.php
http://www.freeukclassifieds.co.uk/
http://www.nationalads.co.uk/
http://www.findit.co.uk/
http://www.iclads.com/
http://www.ad-mart.co.uk/
http://www.annonz.co.uk/
http://www.localads.co.uk/
http://www.justoneuk.com/
http://london.adzooks.co.uk/?ppc=true
http://www.ypoi.com/index.aspx?LanguageID=3