I've been meaning to do a tutorial about this for awhile and keep forgetting to do it.
I use Magnets to hold my figures up. K&J magnets make some very strong Neodymium magnets. For guys I use four 3/8th x 1/32nd magnets #D601.
http://www.kjmagnetics.com/products.asp?cat=10
First I sand some of the detail off the bottom of the boot. I know this sux but who really looks at the heels of the boots anyways. Then I glue two magnets to the bottom of each boot. One on the toe and one on the heel. I have played with cutting the side of the boot open and gluing the magnet in side. This also works, but not as well, Your choice. Then I use either Obitsu metal bases from Junky Spot,
http://www.junkyspot.com/obindex.html
or those thin metal cigar tins as bases. Anything steel or iron will work. Here are a few pix of some of my figs with magnet bases,
Sorry, I'm not the best at posing figs. But you get the idea.
I'm not saying this is the end all to beat all. But it does work. I wouldn't leave a figure standing on one foot six feet off the ground all day. I'm sure at some point it would fall. But I have left figures standing at a charge with no problems. I have had figures fall over using this method. But then I live with a herd or rhinos so I think that is the problem honestly.
One more thing. I wouldn't put figures with these magnets on top of your computer. These magnets are pretty strong ( I've had them jump four inches to get to each other). I don't know how good it would be for your hard drive.
If you have any questions pm me and I'll see if I can help.
Paul