BYOC is exactly what you’d hope it would be. Citrix grants a $2,100 stipend every three years. Employees purchase the laptop of their choice, be it an $800 Dell, a Toshiba tablet, 17-inch MacBook Pro, or $4,000 gaming machine. The only requirements: a 3-year support contract, up-to-date anti-virus, the ability to connect to the corporate SSL VPN, and, of course, running XenApp for delivery of all required business apps.

http://www.informationweek.com/blog/main/archives/2008/10/citrix_tries_by.html

I think this is a great idea and actually know a few employees who have opted to do this, but the one thing that I don’t like is that the $2,100 is taxed, so you really only end up getting around $1,400 after taxes, and then the computer you buy then has taxes added on depending on where and how you purchase it, thus dropping that $1,400 down even further, to something more like $1,200

But Then again you get to pick the exact computer configured the way you want!