Usually the bottles they came in, although we have these cute Tupperware shakers for our salt and pepper which don't leak. And another little Tupperware for our Colemans mustard.
The Dormobile has a spice rack attached to the inside wall above the left rear window. I went to look on TeriAnn's site for a photo, but couldn't find one.
usually carry thing in the original bottles too. but last weekend I picked up some shaker lids that fit on 35mm film canisters. I bought four of them so I think i'll give them a shot this year. they fit really tight so I don't think they'll spill. and I also picked up some clear 2 and 4oz nalgene bottles for olive oil and other wet items. I figure I don't use alot of season on a trip so maybe I can save some room by packing smaller quanties.
I bought new film and trashed the roll since I have a DSLR. I washed them out good. Only a short section of actual film comes in contact with the container so I don't think there's much to worry about with new containers, but I see your point with using old ones.
I use a few of the type that Weezerbot showed. Places like REI carry empty ones, so that you can choose your own spices. If I'm going to be using more than those will hold (such as salt, pepper, parsley etc) then I leave them in their original bottle as others have mentioned. We also prefer to buy our spices at Whole Foods because refilling a bottle of ginger costs about 1/4 the price of the original bottle of ginger.
Great thread, we've been doing the full size shakers in zip lock bags in our chuck box. We have been wanting to tighten and lighten things up and spices are a good start. I googled "Kenyon spice shaker" and found a handful of retailers for those looking for alternate sources
This place has them for $2.50 for empty or $5 for the full 4 compartment unit. Now I just need to spend another $95 so I get the free shipping http://www.scoutgear.com/equpi110.html