The site now hosts a map of the registered members of the PHP-GTK community. You can find it here.
On that occasion, I reviewed the coordinates given by existing members and noticed a good number had visibly inverted latitude and longitude; so I inverted them again to place them where it appeared to make more sense (are there really PHP-GTK devs in the middle of the pacific, or near the South pole ?). So you may want to double-check your coordinates to make sure the values are correct, because it's likely I've not found every error. Remember: latitude is the North-South one, typically from -68 (Ushuaia, Argentina) to +64 (Fairbanks, Alaska), and longitude is the East/West one, from -150 (Anchorage, Alaska) to 174 (Auckland, New Zealand).
Room for improvement
What I'd really like is for the PHP-GTK Brazil community to allow us to list their members here, just like we already offer that access with the geo-nick API.
One small thing: see the GTK marker on the map ? If someone with better graphics skills can come up with a better set of Google Maps markers than this one I just created, by all means send it, so everyone can benefit !