With the holidays approaching faster, Microsoft's offering a great holiday present that goes by the name "Microsoft Home User Program (HUP)".
If your company sets things up properly -- and it only takes a little bit of effort -- every employee who's covered for Office under the Software Assurance agreement can buy a key for Office 2010 Pro Plus for $9.95 (price varies outside the US). The key is good for one PC, and it doesn't have to be a work PC -- any PC used in the home is fine.
All your user needs is a work email address, which's verified in advance by your company's SA admin, and a program code that's available online to your SA admin. There's a full animated description of the process on HUP site, and additional info for bulk orders, if you want to hand out DVDs to your users, on Digital Marketing Portal. Microsoft even has flyers, bulk email templates, and reams of online information to make it easier to get the word out to your employees.
If it's so cheap and easy, why don't more users know about it? Part of the reason is a common misconception among SA admins that the company is somehow "on the hook" to look after HUP licenses. That isn't so. Microsoft's official position:
As the Volume Licensing customer you aren't responsible for your individual employee's compliance with the HUP end user license terms. Those terms are between Microsoft and the individual employee. We do require that you limit HUP access to employees and tell them when they should discontinue use of the HUP software, for e.g. if your SA coverage ends or the employee leaves employment.