I have to say that I find the culture in the UK does not generally support street harassment (although London sounds like an exception judging by some posters' experiences). I've had very few experiences of street abuse since being here.
When I lived in Brussels, the street harassment issue was a daily concern. It was literally impossible to go outside of your door in that city without being harassed (as a woman - men were oblivious to the problem). It didn't matter if you were on your way to work in a suit in the morning or out in the evening with friends - the men were always there, hanging around in doorways, shouting at any woman who went past. It was a huge issue for all of us women were living there as part of programme working at an international institution. We talked about it all the time.
I had friends who were kerb-crawled, abducted in cars (she managed to escape) sexually harassed, groped etc. One woman on our programme was abducted and raped. The response of the people running the programme was to remind us all that we needed to be cautious about where we went(!!).
I regularly was shouted at on the street but my French wasn't good enough to think up witty replies so I would just tell them to 'fuck off' or give them the universal one-fingered salute. They seemed puzzled by my reaction to their 'compliments'. Apparently in French culture (according to French friends), this kind of public abuse is viewed as a compliment! On one occasion I was spat on - I was sitting on a bus waiting for it to depart when some guy came up to the window outside and started leering at me and making kissing motions. I gave him the finger. He then got on the bus and spat on me(!). Could have been worse I guess. Another time, a group of friends and I were walking to a bar in a slightly sketchy area and these two little runts came up trying to grope my friend and isolate her from the group. I went into a completely blind rage and grabbed one of the little chaps by the shirt collar, as if to lift him off the ground, shook him and told him to get the fuck out of there or I'd kick his head in 
. Looking back, that was slightly foolhardy as he could have had a knife and I hasten to add that I am of a slight build so my threat was pretty empty(!) but I was in a blind rage and I kind of sensed he was just a little twit anyway.
It would be great if the threat of violence from a woman weren't so empty and these men could be genuinely scared into stopping their behaviour. After all, they would never go up to a guy in a bar and grope his bum or ask him to give them a blow job because they'd be scared of the violence they'd get in retaliation.
Anyway, great to see that people are out there fighting against this and keeping up awareness. I loved that woman's website, linked to above, where she listed the wankers she'd encountered while cycling, took photos of them etc. This is the best way to get at these guys - have a policy of zero tolerance and name and shame the losers.