Thanks for the kind comments. The instore was really cool. Steve played four songs (including Townes' "Rex's Blues"), Allison two solo, then they closed with a duet on "Days Are Never Long Enough". They then signed items for us lucky fans!
As for my camera, I have a Canon Rebel XTi, and I use a Canon 50mm f1.4 lens, which allows indoor photography without a flash. I think it makes much nicer photos and is a helluva lot less obtrusive to the performers. The only drawback is with the 50mm, it takes pictures a little "closer" than a standard 35mm (hence it was a little tough to get Steve & Allison together in most of the pictures). Canon also makes a 50mm f1.8 lens for less than 100 bucks, and it takes just as nice indoor photos (construction is just a little flimsier). But if you have any kind of 35mm SLR camera, I'd suggest trying out some other lenses and tinkering with the aperture settings. It sounds more complicated than it is - I assure you that I am a rank amateur when it comes to photography.
One last note - I got my tix for the Houston show from SteveEarle-dot-com, and my seats were dead center, first row! So if you're wondering how good the tix are for the presales, I'd say pretty damned good.