I started with kerry's idea. there is a frequency counter library for the arduino and that is the key. lm301 (iirc) as the oscillator and you just connect L or C or R at the right points, get the freq and do the math.
I started building one, here, in a small box, but never finished the code. the hardware works great, though.
I used my own LCD display board (the LCDuino; you can buy them at amb.org as bare boards) which contains the arduino 328 chip, a port expander for lcd i/o, a real time clock chip (not that you need it here) and even a motor pot h-bridge (again, not needed here but used for other projects). there is an adafruit 3v to 5v dc-dc upverter, an lm310 (again, I think that's what I used) which is the standard thing you see, such as in kerry's write-up, and even an xbee for remote programming (!) and remote data logging, if you are so inclined.
I may be able to find the firmware/src I used, but like I said, its unfinished and I'm not sure when I'll have time or interest to complete it. getting the hardware done was most of what I wanted and after that, I kind of lost interest in completing it