Yes, but usually if I recover something, it is from my USB stick or from a memory card.
I don't think, that e.g. browsing the internet would affect the recover process.
edit:
I think that Recuva should either hinder the user completely to work or allow him to minimize the program. Look at Defraggler: I don't think that it is wise to work intensively with the C drive while defragmenting it, but you can minimize Defraggler without any problems and continue working. So why not with Recuva?