133FSB->DDR266=PC2100 is what I'm using. I've seen the calculations of all the other's you've listed. To get the DDR FSB rating of the memory you want - eg PC3500 - divide 3500 by eight to give you the double the actual FSB frequency. This way PC3500 memory work out at running on a 437Mhz (read 433Mhz for this purpose) bus.
So, for your memory calcs,
DDR266 = PC1600 should be 2100
DDR300 = PC2100 should be 2400
DDR333 = PC2700
DDR400 = PC3200
DDR433 = PC3500
So for 1600 read a 200Mhz DDR fsb, or running at 100Mhz actual.
Sorry for raining on your parade cullam3n - I don't mean to be a pedant or anything Hope this helps anyway.