My setup is:
 
* Intel Core 2 Duo E4600 2.4GHz currently @ 2.77GHz
* ASRock 4CoreDual-SATA2 Motherboard
* 2 x 1GB DDR2 PC2-6400 800MHz Dual Channel RAM
* Arctic Cooling Freezer 7 Pro
* ATi Radeon 9600 Pro Ultra AGP x8 GPU Card (due an upgrade soon)
* 120mm front intake fan, 80mm side intake fan, 80mm rear exhaust and thermaltake rear PCI exhaust fan
 
I currently have it overclocked to 2.77GHz and it is stable after a 2 hour custom test using OCCT stabilising tester. My CPU-Z stats are:
 
CPU
Core Voltage: 1.296V
CPU CoreSpeed: 2759.9GHz
Multiplier: x12.0
Bus Speed: 230.0MHz
 
Memory
Type: DDR2
Size: 2048 MBytes
Channels#: Dual
DRAM Frequency: 306.7MHz
FSBRAM: 3:4
4-4-4-12
Command Rate: 2T
 
The above are the settings after OCing to 2.77GHz. SpeeFan 4.34's reportings are:
 
Temp1: 28C
Temp2: 28C
HD1: 23C
Core 0: 23C
Core1: 24C
 
I've ran the OCCT Stability Tester and it confirms the above settings are stable when put under a 2 hour custom mix torture test. The maximum the temps of each individual core gets to under load in SpeedFan is 44C.  I'm a newbie to OCing so I am chuffed that I got this far. Does anyone see any way of increasing the above so I can try and OC to 3GHz?

Probably would be to grab a good P35/X38 motherboard like the P35-DS3L. Or bump up voltages + relax timing or smiler if OCing RAM. Be aware that your PCIe socket is limited to x4. VIA is not the best chipset when it comes to OCing, even the 650i is better.

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My 1st PC(2003) OCed/Built
E2180 @3.2Ghz + P35DS3L +8400GS (700/475 OC)