On the news last night, reports of Greeks taking their money out of their (Greek) bank, and putting it in our banks where they think its safer.
Certainly if Greece exit it would have an impact, but we are in a better position than most of Europe, our banks hold relatively little Greek debt.
Trade would be hit, but thats a short term issue, and as Europes economy improves, ours would too, more so than many others. I have seen several predictions that show that within a generation the British economy will out strip Germanys, not much sight of that yet though.