Got 50 to 70 pounds spare, any cool camera equipment i could get?

Really wanted a new lens, but i'm dreadful at saving, so waiting until i have the money all at once to get a 50mm. Take a look at my photography www.flickr.com/bridgetphoto

any cool equipment i could get for that price? I have a Nikon D5000

also i had a look at 50mm Canon film lens, if i got an adapter would that work with my Nikon D5000 DSLR, i know it would be manual focus but that doesn't mater.

Seeing as you seem to like portraiture, you ought to experiment with off camera flash.

A Yongnuo YN560 fully manual flash will cost around £50
A set of RF602 radio triggers (one transmitter & one receiver) will cost you around £20.

It would be a great intro to lighting and can be added to as funds become available. Learning about lighting is a good step to take - check out the Strobist blog (Lighting 101 & 102 archives) if you are new to off camera flash;
http://strobist.blogspot.co.uk/2006/03/lighting-101.html

No - the Canon lens will not work on your Nikon & I don't believe any adapters are available. A Nikon 50mm f1.8 lens is around £100 - this would also be manual focus on your D5000.

Underwater case

Save your money, spending £50 here and there's much worse than investing a few hundred pounds later on on something more serious. Additionally right now it's a time to be learning skills rather than blowing money on useless trinkets.