Can I get the Firefox Start page to use Google.co.uk not Google.com?

Yes! The built-in home page uses the same search engine as the search bar, which is the one that normally appears on the main toolbar and has a little "g" at the left end. So I would expect the search plugin to use the .com site in both places. If you do not have a Google search plugin specifically targeted toward the UK site, you probably can get the results you want from the plugin for "Google UK - the UK" on this very long page: http://mycroftproject.com/google-search-plugins.html Does that work? If not, search plugins can be edited to send your search to the correct URL, but it might take a little experimentation on Google to track down the parameters.