I recently won a set of Traction Jacks:
http://tractionjack.com/
A new company just getting off the ground. Their party piece is that they fold in half making them easier to store. They're also made in the USA, so that's a nice plus for those of us who like to spend here when we can.
(I'm not being super ra-ra-ra, only buy American, etc, but if I can keep my money at home I'd rather do that than send it to China)
I have not yet had a chance to use them so I can't comment on how well they work. They do appear to be well made and sturdy. The pair of them weighs in about 27 lbs as I recall and the knubs seem pretty aggressive. From my initial impressions I have no complaints.
I may get a chance to go play in the mud tomorrow. If I do, I'll report on what I find. Wish I had had them last weekend in the snow to try out, but shipping was just a day late for that trip.
If you are space challenged or need to store something like this IN the vehicle instead of on a rack, you might want to give them a look. If anybody else has tried them, I'd love to hear your thoughts.
No affiliating, yada yada yada. The owner donated a set to our club and I won them in a raffle. I wasn't specifically in the market for a set of ramps, but I have been in a few situations where I could have used them so they should make a decent addition to my gear.