Differential GPS beacon receivers

[asteffes]

Do any of you use a DGPS receiver with your primary navigation GPS? I was looking into playing with DGPS a little, but the receivers I've found are expensive. The Garmin GBR-21, or something like it, is what I'm interested in. I've found one on Ebay, but if there is a cheap kit or alternative I should investigate I would appreciate any advice.

[GeoRoss]

There are sometimes stations in your area that publish their data on the web. This is usually good for getting down to the 1-2m resolution or better depending on a host of conditions.

Ross