I've used fujilab.co.uk and am very happy with the results and for straightforward orders the prints get posted next working day. A bit expensive for small orders as they apply a blanket £1.50 handling charge so it is best to send a lot off at once.
Their software does not run wildly all over your computer and is only there as a means to upload your pictures to their machines and hold their price list.
Beware of smaller shops offering prints from digital who say it will take a few days and put your memory card in an envelope. They don't have a machine on site and you are running the risk of them losing your card just like a roll of film.