In addition to my above post...

This was posted at RoadBikeReview by Zoikz in 2006...

One of the central limitations of sports medicine research is generally these studies are done on very small samples. Because of this they have very little power, ie. their conclusions are really not statistically significant. When you look at any given topic there are multiple small studies with differing conclusions. Sodium phosphate is typical, there are studies on either side; benefit, no benefit.
To be fair these studies are generally poorly funded and technically difficult to perform. It would be very, very difficult to conduct the large placebo based randomized trials everyone in medicine loves.
One word of warning though, look at who funds these different projects. Often these research studies are conducted by researchers or labs with a vested intereest in the product they are assessing. Accelerade is certainly a good example of bad science conducted by biased researchers.
My take on phosphate is it probably won't hurt so give it a shot if you want. Doubt it does much of anything though.