I use a case much like the one stewart got from his work. Though i got mine through harbor freight. And it comes with foam already in it as well. Not the greatest foam but since my army is magnetized it does its job.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39196

Best of all its relatively cheap

I have a large (12"x17"x5") clear plastic case, that I epoxied a large piece of sheet metal to the bottom after cutting it to size. With rare earth magnets (or 2) in the base of each model, I can barely get them to move if I try. They hold vertical, upside-down, you name it. I could probably use it as a standard suitcase if I wanted to. I don't, but I could It's a relatively cheap solution - about $18 for the box, $4 for the sheet metal, and the magnets are $0.17 each. I used to use Sabol, and still do for a lot of other stuff, but counting the number of trays I'd need for a hundred-strong army... <shudder>

I've got some of the flex steel on the way from Litko to line my movement trays with, and depending on how the magnets interact I may magnetize the bottom of the trays too... Magnets magnets everywhere!

Search KR Multicases, they do gw style trays with hard cardboard cases for £20. That gives you 144 slots for minitures. THey also do a pick'n'mix selection where you can choose what trays you want. Eg. a double depth, single depth and a double depth push out layer for monsters etc.

They do also sell hard cases, and i swear by them, never failed me once.

I actually use the army cases. On cavalry and my other bulky models I cut out some of the foam walls in order to fit them. As for the slann/carnosaur/stegadon I have one of the red warhammer cases with the large foam insert.

I second that, I have several KR multicases and they are amazing. You can get them in North America for around 25$ from FRP Games in California. Cheap, super easy to modify and customize, you can write directly on them to label them easy, and even though they are cardboard they are damn sturdy. I highly recommend these as well.

Yeah KR multicases have served me well, quick delivery good price and helpful staff.