I use the Lynx levelers too. They can be found at Wal-Mart if you want to pick up a set locally (if Wal-Mart can be considered local...).
The one time I don't like the Lynx as much is once you start needing a higher stack. You only really get "half a block" on each subsequent level and it takes more and more since they go up in a pyramid.
A friend has a pair of plastic ramps that are nice, but they are much bulkier to store and not as versatile as the Lynx blocks (you can only use them on two wheels, unless you get more than two and that would just be a silly amount of storage space). I haven't had any trouble getting the front wheels up onto the Lynx blocks even with 2WD. Maybe because I grew up driving on snow - developed that feather touch
Side bonus, one or two Lynx blocks make a handy "set down" for a trailer tongue wheel, and keep it from rolling around too (there is a divot in the center). I've heard of people using them to make a "path" to get out from being stuck but have never tried it, so not sure how well it might work (not that most of you need that anyway, what with the 4WD and all
I'll have to check out the "MOMA looking" red scythe shaped ones - interesting.