Program to identify BPM?

I want to put a workout music list together, but when I do, I end up putting slow songs in by accident. I was hoping to be able to just run my music files through a program to make a music list for me, but I think that is a little too much to ask for

Are there any free software out there that will go through all my music and do this for me?

I tried BPM Analyzer from Mixmeister, but it would only do it for a couple files.

Thanks!

This Lifehacker review says the apps that do this get it wrong 30% of the time.

(note to self: startup idea. BPM analysis software that actually identifies the songs instead; crowd-sourced corrections; ad revenues support the concept; the site lives for a year and makes a few million before others retrofit BPM into their own metadata. Maybe have for-pay API. Who wants to fund me? $30K 50%, six months product and biz development)