Joe Kinder blogged about this a few days ago (although in an unashamed post pointing out that he was given it free) - these removable bolts from ClimbTech. I'll be honest, I'd never heard of the company but they've been around since the 90's supposedly. And I've just noticed that 8a.nu has thrown up a link about them now under a similar title to that which I posted on myself.
But I have to say I was intrigued - not that I see them replacing permanent bolts as it'd be too easy to have them stolen, people move them around, whatever. But that they might be of use in other places, like for example my incident with the bolts in Ireland (I can't find the old post but it's on climbing.ie anyway), where the short bouldery line could have been tried safely, but there would have been no 'unsightly bolts' to leave and cause offense to those that didn't like them.
I'm not saying they'll replace trad gear either, but in sensitive areas, is this an option? all thoughts welcome :)