Lets see, a 2.6GHz Celeron runs at a 400MHz FSB (quad pumped 100MHz) you ask the question "what is the fastest DDR ram that i can take full advantage of?" someone tells you to get DDR memory that runs at 166MHz or 200MHz, and you thank them...
A 2.6GHz is going to use a 26x multiplier so to take full advantage of even 133MHz DDR ram it would require your celeron to be overclocked to (133 x 26) 3.46GHz, do you really expect this or more?
Moving on, you plan to use this untill you replace a broken notebook.
I see three posibilities
1. you can't afford a new notebook, meaning you will be stuck on the desktop for a while.
2. you can afford a notebook but not the one you want, so back to the first reason.
3. you have plenty of money but are waiting on a laptop with more features to come to market, meaning you will be stuck on the celeron desktop again, when you could easily afford more.
Kinda sounds like an oxymoron to me. I can't afford a notebook so I spend money on a desktop that I dont really want and will make the notebook even more out of my reach, or what is on the market isnt good enough so I will use something even worse.
I guess I just don't understand your situation, so I will at least thank you for supporting the economy by spending your money frivolously.