I saw another post on here with directions to build a bike lift, looked neat so I thought I'd give it a shot...Thanks for the link, iandel!
Heres the link....
Cheap lift
And heres mine....Note the eye bolts for attaching tie downs to stabilize the bike.
Just slide it under the bike..(Gotta watch the filter, though, if you put it directly under the filter, it will squish it a little.)
Then give the handle a twist and up she goes. Depending where on the frame you put it, you can lift either the front or back wheel off the ground entirely. Its very stable, too, althoug if its gonna be up for longer than it takes to lube the chain, I recomend using tiedowns to the eye bolts to hold her still.
Not quite a replacement for a bike jack, but a fun and useful little project!