There's a thread over in the Dublin forum about a con man who approaches folk with a sob story:
http://www.boards.ie/vbulletin/showthread.php?t=2057545632
If I'm ever in town (Dublin / any built up area), I'd probably have headphones in and would ignore anyone I didn't know as would probably think they are a chugger / con person / weirdo.
Very rarely would I make a quick judgement, and maybe it may be someone who needs directions etc... but it depends on the location / time.
When back where I live (suburban setting), I've no trouble with people coming up to me as I guess the likelihood of con people / sales person is a lot lower.
So, would you ever speak to a stranger that approaches you on the street?
(doesn't include random people chatting in pubs or more 'social settings')
Maybe you have funny / odd stories of strangers who approached you for some reason and one thing led to another?
Maybe you're now married to them?
Maybe they led you onto a new life?