the InterVarsity Folk Dance Festival (27th-29th feb Exeter uni this year).
I'm a Dundee student (age 20) and I think this is the best young folk event around, most the participants are students and the whole thing takes place around the host university so you are surrounded by young people.
The four scottish universities with folk (well, Scottish country dance) groups tend to go in convoy and have a great time.
www.ivfdf.org has the information and at only £13 for students for the whole weekend it is great value!
My one gripe is that as a Dundee Celtic society comittee member I have to sit through a long comittee meeting to ensure no-one volenteers Dundee to host IVFDF 2006.
And Dave, were you at Towersy last year? I saw you busking over the summer in Chelmsford.