http://www.intellectual-property.gov.uk/   

UK Government-backed portal for Intellectual Property

http://www.patent.gov.uk

UK Patent Office

http://www.european-patent-office.org/index.en.php

European patent Office

http://www.uspto.gov/main/patents.htm

United States Patent Office

http://oami.eu.int

Home of European Community Trade Mark and Design Applications and registrations

http://ep.espacenet.com

Patent Searching and information Site (Note; this site is useful for rough preliminary searching, or to obtain details of known patents and applications but for fuller freedom of use, infringement or novelty searching and advice we would recommend consulting professional advisors, such as ourselves!)

http://www.cipa.org.uk

CIPA  Professional body of UK Chartered Patent Attorneys

http://www.itma.org.uk

ITMA Professional Body of UK Trade Mark Attorneys

http://www.patentepi.com

European patent Institute  Professional Body of European Patent Attorneys

http://totallyabsurd.com/absurd.htm 

Includes weekly updates listing some of the more 'off the wall' inventions being patented!