It really does depend on the type of party / time of year / indoor or outdoor / and any activities (!) that may or may not take place. It's pretty sure there will be some people smoking, and a degree of rackaboogie type shenanegins, so exposed feet may be risky all round.
Flip flops are called thongs in Oz! If you are in Oz you can wear anything, but in blighty it's a bit cooler. Flip flops are an antifashion statement. ie only ok if party is on beach, and it's hot, but why care what others think? If you feel good, go for it. Life's too short and all that kind of stuff...
ha ha ha ha ha indie! i think it depends on the dress code. if it's casual then wear them. also it depends on what your flip flops are like... minging and dirty and old or pretty and new? also if you are comfy in them then wear them, there is nothing worse than feeling uncomfy in pretty but silly shoes if you have to stand or walk at all! ask your mates - what are they wearing? basically wear what the hell you want! and have a good time. xxxx
With the right styling flip flops are right for anything, they're bare feet with soul protection! So if you have pretty feet or good looking toes - get 'em out and about. See flipflopflo.co.uk if you want to see flip flops with real style. Kate Moss and the fashionistas all have a pair or tow of thses handy or should that be footsie?
I recently changed into my flip flops at a wedding so I reckon wear what you want HOWEVER I warn you, they are not easy to dance in, too slippy, so i ended up in bare feet instead.