Thanks everybody, looks like decimal degrees is the format to go with. Our local GIS expert came to the same conclusion. Spatial db extensions are not an option for us at the moment; we've got to store them as strings.

Mark

----- Original Message -----
> On Jun 28, 2012, at 3:46 PM, Matthew LeVan wrote:
> 
> > I'd think it would depend on what you plan to do with the
> > coordinates once
> > you have them stored.  If you intend to do anything at all
> > complicated
> > (spatial queries, KML generation, your own custom maps, area/volume
> > calculations), you might want to consider a spatial database
> > extension (
> > http://en.wikipedia.org/wiki/Spatial_database).
> > 
> > I've used the SQLite SpatiaLite and Postgres PostGIS extensions,
> > and
> > they're fairly straightforward to setup.
> 
> 
> Agreed.  If you're going to be searching on them (places w/in 50
> miles of (x), closest to (y)) ... spatial database extensions are
> the way to go.
> 
> If you're just going to be returning them for display, it probably
> doesn't matter so much, but odds are someone in the future is going
> to ask about it.
> 
> (and that being said; I store two copies of most anything coordinate
> or unit related ... one for searching that's well normalized, and
> one for display purposes ... database normalization be damned)
> 
> -Joe
>