Geo location

I would be interested to hear from others who have implemented a mapping facility on a membership site.

I do need to see where our members are on a map but have not been able to crack some basic problems. I have looked at GMap/Location and Open Layer modules and I can see that both could work. However, I have a huge problem with generating the location data for 300+ existing users in Ireland (ignoring the 2000+ international members). Ireland has no postcodes and very non-uniform postal address formats. There are moves to introduce a GPS based postcode system (see www.myloc8ion.com/) but I can't see it happening soon.

So users are going to have to find themselves on a map by searching and visual methods. I can't do it for them because some places just can't be found unless you know where they are! I would be interested to hear from anyone who has asked members to generate their location data and how it was entered into their profile etc.