My Macbook has been glitching lately.
It's been flashing black across the screen, which stays for about a quarter second, and occasionally it freezes up.
Specs:
- Model Name: MacBook Pro
 Model Identifier: MacBookPro3,1
 Processor Name: Intel Core 2 Duo
 Processor Speed: 2.4 GHz
 Number Of Processors: 1
 Total Number Of Cores: 2
 L2 Cache: 4 MB
 Memory: 4 GB 667 MHz DDR2 SDRAM
 Bus Speed: 800 MHz
And more specifically, my video card specs:
NVIDIA GeForce 8600M GT:
- Chipset Model: GeForce 8600M GT    
 Type: GPU
 Bus: PCIe
 PCIe Lane Width: x16
 VRAM (Total): 256 MB
 Vendor: NVIDIA
 
Also what I have running:
Google Chrome
Kerbal Space Program