Google the Ikea Jerker desk. They discontinued the standup model - or rather the model that could be configured as such - but you'd probably be able to find one used on craigslist or ebay.
It is designed for this specifically, although it is big, so you need a good deal of space. I've been using one in my home office for about 7 years now.
It is designed for this specifically, although it is big, so you need a good deal of space. I've been using one in my home office for about 7 years now.