In my new band, we play somewhere between Muse/Radiohead/Sonic Youth, and we've just got this new bassist in. And both me and the bassist love funk and improvising - no-one else in the band does though!
And so now, everytime a song finishes - you know what its like, guitar in your hands its impossible not to play - so I'll usually end up playing some hanging, funk-style 7th chord, and away we'll go on a funk odyssey. Not sure the other guys really dig it though!
I guess this is overplaying in a different sense to how I started this thread!