Putting your laptop on a bunch of boxes puts a lot of strain on your arms. Of course this also doesn't work if you have a big display on your desk.
I'd be interested in hacking a standing desk that is
1) ergonomic
2) offers support for both laptops and big displays
3) has a usable keyboard drawer for both standing and sitting position
If all else fails we'll just make a living selling desks like that. (and no, geekdesk does not meet all requirements)
[1] http://www.infologix.com/images/usr/ergonomic-computer-cart....