2 questions.
1. Is your current Dothan 400mhz or 533mhz fsb chip (730=533mhz, 735=400mhz)?
2. What chipset does the laptop have?
(you can get this info from cpu-z)
If it is a 400mhz fsb 735 Dothan chip and intel 910/915 chipset, you can check out the pin mod/volt mod sticky in this section.
If it is a 400mhz fsb 735 Dothan chip and intel 855 chipset, you can upgrade to the fastest 400mhz fsb Dothan (2.26ghz?).
If it is 533mhz fsb 730 Dothan chip and intel 915 chipset, you can upgrade to the fastest 533mhz dothan or downgrade to a 400mhz fsb 725 Dothan/735 Dothan and try to pin mod/volt mod it. 725/1.6ghz Dothans pin mod to 2.13ghz, and 735/1.7ghz Dothans pin mod to 2.26ghz.
Note that the 400mhz fsb Dothans are not garanteed to pin mod even with extra voltage. The safest thing to do is upgrade to the best cpu that your model supports.