Hi this is my new project and I would like to share it. It is free Uk company search. You can search all UK companies by name, number or you can search officers. The link is:
http://www.123companysearch.co.uk/
The main benefit is: if you search google you get so many web sites usually not really related to the company you are looking for. On this website you'll get exact information searched company.
Next use can be if you are looking for company name. So you can simply check if you desired name is taken.

Hopefuly you will like it, and if you have any suggestions, or comments use contact us page.