Just been reading the comments on Darren's (mirax) latest excellent self-portrait and noted that he's doing a course. I too have just enrolled on a course and found that the college I'm attending is registered with an excellent site for student software licences. If you are a suitably enrolled student, and want a copy of Office 2007 Full Enterprise Edition, that can be installed on one desktop plus one additional mobile device (e.g. laptop) for £35, then take a look at:
http://www.software4students.co.uk/
They do Adobe software at much reduced prices too, but the criteria for getting a licence key are much tougher. I'd have to be on a full time 2 year course equivalent to a degree to get Photoshop cheap, but ironically enough, if you have a child in full time secondary school education, you can get a student licence. CS4 for £148 is a bit of a bargain, but of course, it's only your children that are allowed to use it.