Hi guys,
Not sure whether you've seen this program, but it's very similar to dartfish (though it might not have quite all of the functionality - Steve, could you comment on the differences?). It is open source freeware, however, so give it a go if you want. I've had a quick look through, and it looks well made with some good options ofr all the basic analysis you might want to do. Its good for plotting and analysing follow-throughs, has a chronograph, perspective grid for measurements, magnifier, angle markers, etc.
http://www.kinovea.org/en/
Features overview can be found here: http://www.kinovea.org/documents/Kinovea.0.7.6.en.pdf
Andrew Russell