Anyone written any apps for GPS-enabled phones?

[Abu AbdAllah]

Bismillah. This idea would take advantage of the GPS-features of
phones to let a mobile-app or a mobile-web-page submit data to
prayinjamat.com.

Many people have, alhamdolillah, used the web site to submit their
musallah or other jamat to prayinjamat.com. But they have to at least
be on a laptop to use the current method.

This idea would let people submit the musallah to the web site while
they are there in person -- and it should be the easiest method
possible (for the end user).

When people want to add a musallah to the web site, they would just
use their GPS-enabled phone or similar mobile device. Ideally the
person would have to enter at least one name for the musallah (many
masajid are known by more than one name). The GPS coordinates would
be supplied by the phone. And the message could be sent via e-mail,
SMS, or even via Tweet if the Twitter API idea works out, bi
'idhnillah.

The hard part is getting the phones to submit this information. Does
anyone here have experience with this kind of phone-app?