I inherited an old Trav-a-Dial that I am hoping to get attached soon to my lathe. I got used to using one in the shop of my mentor and really like the way I can follow that sweeping arm on the dial. A simple magnetic base dial indicator as others have suggested would be my second choice.
Froggie
Just some interesting background info on magnets for any kind of project.
http://www.leevalley.com/en/hardware/page.aspx?p=40077&cat=3,42363
All three of my dial callipers are magnetic. When the cursor (the part with the dial) is held with a magnet it creates a lot of drag on the slide.
UPDATE: I experimented with a magnetic mount for a dial calliper because it holds so well.....BUT... after running the slide up and down a few times it magnetizes the callipers! Not good. I do not want my callipers attracting and holding steel chips thank you.
Back to the drawing board for a mechanical style mount.