this site datum/lat long conversions is pretty slick - you can enter coordinates in one datum and convert to another, lat/long to utm and back, etc... (continental US only, sorry).

There's another site I only have bookmarked at work that gives utm coordinates on either the 1927 or 1983/84 datum (switch back and forth at will) as you move your cursor over 1:24k quad maps or sat. map. I'll try to send that one tomorrow if anyone is interested.


Both can be handy, esp. if say, your crew has collected data on different gps units set to different datums...