I recently bought the Joby suction cup with GorillaPod arm mainly as a replacement for numerous suction based in car phone holders which have frankly been terrible. The Joby cup can be had from between £18 and £25.
The first thing I noticed is that this thing REALLY sticks to whatever glass or shiny surface you stick it too, it's really not going anywhare without some pretty solid effort. However there are surfaces that It won't stick to at all, such as wood, bricks, wallpaper or leather etc.
The GorillaPod arm I am slightly less impressed with, but only slightly. Overall it's solid and absolutely does what it needs to do, but In find it slightly clunky in operation.. which is only a minor complaint and hardly unexpected at this low price point.
Though I initially bought the Joby as an in car phone holder, I am sufficiently impressed with it's sticking ability that I am going to [carefully] venture into using it as an external camera holder for moving car shots.

