I think APRS is nice, although a bit expensive to get going, as is D-Star
which has data features too.
I bought my 2 meter set up from Byonics (http://www.byonics.com/microtrak/)
and have it up and working for less than $200.

I have read that the only equipment required for an Igate was a receiver, a
computer with a sound card and an internet connection. I have a scanner
that covers 144.39 and a internet computer with a sound card. However I
have not been able to get the software to function yet. This guy makes it
sound easy (http://home.hiwaay.net/~sbuc/journal/igate.htm).

There must be some I gates around the area because there are Hams showing up
on APRS.fi

I am still trying to understand TNC terminal node controllers and what they
do. I have a lot to learn.

Gary