This year you can use your DTMF HT to report where you are hanging out at the Hamvention to about 120 feet just by sending two digits for your XY coordinate.
Just print a small copy of the map on www.aprs.org/aprstt.html for the XY grid to carry with you. Everyone in the world (including those at dayton) looking at an APRS display will be able to find you. See the live map here: http://hamvention.aprs.fi/
For example, the Bar at the corner of the arena is at coordinates 65 and the AMSAT booth is near 32. To send these xy coordinates into APRS using DTMF, just tune to the APRStt frequency 146.58 and hit the keys Bxy* then hit the key to send your DTMF callsign from memory, and bingo... Your transmission is received by the APRStt engine centrally located (near grid 44) and converted to packet on the APRS channel for the world to see.
Using the same paper map above, if you have a TH-D7 or VX-8R you can also report your position to 60 feet without a GPS by just bumping the hundredths of a minute of lat/long to the aa/bb grid located on the same map above.
LAT 3949.aa LON 8415.bb
Print the map from the www.aprs.org/aprstt.html web page. It also shows you how to program your DTMF callsign so you can save it in your HT's DTMF memory.
See you on the map at Dayton! Bob, Wb4APR