Oracle Database 10g Express Edition (Oracle XE) is being used all over the world. If you are using Oracle XE why not add yourself to the map - see the OracleXE group on frapper - http://www.frappr.com/oraclexe.
You can also find other people in your area using Oracle XE as well.
Simply add yourself to the map (no registration required) and join the community!
You can also check out the Frappr group for HTML DB users ( http://www.frappr.com/htmldbusers ) and see who is using it in the world.