overstaying visa

Can anybody tell me the repercussions of overstaying your visa?  I have been in the UK on a year long visa (expiring March 21) as a full-time volunteer worker for CSV.  I haven't had much time for exploration and was hoping to spend the next couple of months travelling the UK, returning in mid-May.  Are there any means of going about this besides the mighty expensive Croyden application route?  How about leaving the country and returning after the expiration date?  Any information would be greatly appreciated.

Not sure about the "official" rules, but it seems to me that as long as you aren't hoping to come back to the UK very soon on another visa (or apply for another visa) they probably won't know if you stay on a bit.  But that's purely my uneducated opinion!  

I personally wouldn't risk going out of the country and coming back so quickly, but I have heard of it being done successfully!  In which case, you'd have up to 6 months before you weren't 'legal'.  

I guess as long as you've got the funds to support yourself for the time you want to tour around, and as long as you can prove that you do intend to leave after 2 months, they probably will be fine with it.

tracey popped over to rep of ireland  on expiry of her visa and came back after 4 days no one said anything.

she flew from cardiff on ryan air it was very cheap