I've nearly finished my second year at uni now but I still keep in touch with loads of my high school/sixth form friends. There's a close group of about 12 of us.
I don't speak to them too much when i'm at uni and the last time we were all together was New Years, but as soon as we're all back for holidays, it's like we've never been apart.
I think if you're really great friends and have been for a long time, then all it takes is a little bit of effort to organise a few get togethers.
As soon as we're back, the first thing we do is book a carvery.
... or decide where we're having Chinese and movie night.