Applying web 2.0 applications

While I am generally amused by--and often enamored of--the vast array of web 2.0 applications available today, I have always maintained a niggling thought that some applications might exist solely for their own use: that is, they are what they are, and maybe there is not always an effective or worthwhile educational application--and by extension, there might be a good bit of wheel-spinning or wasted time in trying to devise ways in which to use tools that were not designed originally for the specific job. That is the potential down side of technology in this case. The potential upside is that there likely are countless effective ways to apply web 2.0 tools in schools.