I'm not sure if this is "old news" or not, but here is a link to Helmut Dersch's latest "experiment" - a bargain basement solution for controlling a camera over USB, but without a laptop. The premise is also that it utilizes WiFi and a browser-based Linux controller so the true "host" can be nearly anywhere.
http://webuser.hs-furtwangen.de/~dersch/gphoto/remote.html
I can imagine situations where time-lapse HDRs could be generated if either HDRcapOSX was recompiled for Linux, or if PTP camera control could somehow be "passed through" the Linux controller from an OSX remote system. Many other possibilities for the slightly more Linux-y folk...
-Mark