Approximately 60 to 70. (I'm a 30-something guy). Stopped counting around 50. I'm wouldn't have called myself 'promiscuous' (sp?), it just happened over a period of time when I was single and looking. I was actually very careful also but of course I realise the risks that were involved.
I imagine this number might be considered high, but maybe not ? (but obviously higher than those that have stayed in a stable long term relationship, which I indeed prefer far more than anything).