Okay, its actually very simple - I have a regular desk with an LCD on a nice arm mount... I built a raised platform to sit on top of the desk to hold my wireless keyboard and mouse. When I want to stand for a while, I just raise up the LCD and tweak the angle, grab this platform off my bookshelf, and keep cranking. Its really easy to switch in and out, and its hand built so its tuned to the perfect height... ergonomically.
Here is a quick close up of the construction - its just a nice plank of that laminated particle board crap they use for Ikea style desks with 4 legs made out of 2x4 pine.
