Trimble VRS - TTT

I didn't see Bill Henning's document referenced in the discussion below.

Here it is: http://www.ngs.noaa.gov/PUBS_LIB/NGS.RTN.Public.v2.0.pdf

I've used it on boundary re-surveys. It worked great. Checking into a nearby NGS monument a couple of miles from the site was within 0.02 feet from published coordinates.

You should follow the guidelines and re-observe a number of points on a different day at a different time, but it's pretty impressive. You're dependent on cell coverage however and we can't always get that everywhere.