Thanks for the comments everyone.
I redid them so that each tile is a component, as opposed to a complete section. That way you get the benefits of smaller campaing file size, and also the possible varieties are huge with much fewer tiles.
Here they are zipped:
http://www.mediafire.com/?3izm9ngmnm0 (thanks kazinsky =)
Sample cmpgn file:
http://gallery.rptools.net/v/contrib/galneweinhaw/CaveTiles2/CaveTileTest_cmpgn.htmlExamples:
A wall tile:

A different wall tile:

overlap them and you'll get a curvy looking N-S passage, or they could be chamber walls. Or join them with inside corners to get T junctions etc etc.
This first set has 3 of each wall tile:
1 = straightish
2 = concave (curved in)
3 = convex (curved out)
Which give 9 different possible N-S passages, and 9 different E-W passages.
There are one of each outside corner:

And two of each inside corner (while playing around, I noticed the need for more variety here)

With these, you can basically make anything.... almost. Next set, if there's interest, or I find a need for them =) will be offset 5ft so not all the junctions will be in the middle, allowing for easy 10ft passages and other chamber, corner everything else combinations =)
Thought and critisicms appreciated =D