[andrewaylett]

It's perhaps worth noting that this the article is very US-centric. I'm in the UK, and I've never had an opportunity to exercise options that didn't come alongside an offer from the company to buy the shares. And in my experience, it's rare to exercise and hold. Even if you do, you can sell enough shares to cover the tax and keep the rest.

My current employer has (and uses) the right to repurchase any shares I hold at the current "fair market value" if I leave the business. That's also fairly standard for privately-held companies, it seems.