The EThOS service http://ethos.bl.uk has been released as a public beta trial giving you the ability to search for UK PhD theses. You can search for theses by author, by subject or by Institution in the search box and if you wish you can limit your search to those theses that are available for immediate download.
Many of the theses are available for immediate, free, download from the service and if they are not available for download then you can order them directly through the EThOS website and arrange for the digitisation of the thesis letting you know when it is available for download. The first time you place an order for a thesis you will have to register with EThOS but registration is quick and easy and is there to protect copyright in the thesis.
Most universities are making their theses available free however a small number will require payment for the digitisation of the thesis. If you are asked to pay for the digitisation of the thesis or the thesis you require is not available through EThOS then please speak to the Inter-Library Loan staff in your Branch Library.