When I click on coords to show peaks or ranges in a the vicinity of a certain object, the two greatest distances the map displays are 100 miles and 500 miles. Is there any way to add a choice for 250 miles? This would enable one to look at the greater region or state, without showing things two states away. I don't know if this makes sense of is even possible...

All you have to do is to search using a distance of 500 and then overwrite the distance in the URL. The URL starts with the characters below and then follows with the coordinates. Just change 500 to 250 (or whatever distance you want).

"http://www.summitpost.org/object_list.php?object_type=1&map_1=1&distance_1=500"

It's possible and I assume Matt (or the admins) should be able to do that in about 30 seconds (literally). I think a better method would be to just let you type in how many miles you want instead of adding a bunch of values in. I don't think that should take too long either.