Ummm... Cheap, Fast, or Good.
Pick any two.
I went with building my own PICLOG logger. It satisfied the cheap and good criteria. The way I go about soldering stuff together, it took a long long time. It's a bit delicate to hook up.
I don't know if you've already mentioned if you're comfortable with a solder iron or programming microchips before. If you are, then a PIC based datalogger could be the thing for you. A Google search on "pic datalogger backshed" will turn up the how-to guide you need. After that, the complexity is up to you.
You could buy a HOBO, it's a datalogger and has a lot of features and you can e-bay or buy direct right now. Not as cheap as the PICLOG. There area alternatives that can data-log, less cheap than the HOBO may be hard to find.
There are lots of other ways... If you already have the Fluke and a couple of other multimeters, then you have already invested enough money and you can data-log with a pencil and paper! Some people find it enough to just stand all the meters on the same table, run the test, and take a few pictures of the displays together. It doesn't make you famous on the blogosphere... but it works fine for quick tests.