I used to make a really big effort to get chatting to people and going on social events and such and getting involved.
There must be a load of things you can get involved with at college really cheaply, what kind of stuff do you like to do?
You do have to be pretty self motivated though and not just wait until things come to you. Just get nattering to people and suggest going for a coffee or something or get talking about films or music and such and see if they fancy going to see a film or gig.
Study groups can also have a social side and help you to get to know people. Do some studying together then go and have a drink and get to know each other better, you all have something in common already.
There are so many volunteering opportunities too around. Contact your local volunteer bureau or ask a local charity if they need any help with admin or such.
Try these...
http://www.volunteering.org.uk/
http://www.do-it.org.uk/
http://www.csv.org.uk/Volunteer/
http://www.dh.gov.uk/AboutUs/HowDHWorks/DHRecr uitment/DHRecruitmentArticle/fs/en?CONTENT_ID= 4123259&chk=irazhM
Why not try and organise something, a club or similar involving something you enjoy. I used to run a climbing club at college and we used to have a great laugh.