Fragmotion can import .x format and export to GS with animations. The only thing is that the end result is a huge file pending on the amount of animations I guess.
It is also very cheap to register.
Windows XP SP3 Intel Dual Core CPU: E5200 @ 2.5GHz 4.00GB DDR3 Ram ASUS P5G41T-M LX PCIE x16 GeForce GTS 450 1Gb SB Audigy 4 Spyware Doctor with AntiVirus