Just found this thread via Google – the ESR Meter is exactly what I've been looking for!
I've found the internal resistance readout of the FMA PowerLab8 charger very useful recently, as it helped me find out why I was getting poor performance out of some of my 4S1P 5000mAh Turnigy NanoTech packs. When one of the packs was on charge, one of the cell's IR was around 80mΩ compared to 2-3 for the remaining 3 cells! Unfortunately the PowerLab8 is owned by the company I work for, and I'm leaving the company next month! I also prefer the idea of a tester that can give me instant feedback on the condition of cells, rather than having to put a pack on charge to get a readout.
Where is the best place to buy one of Wayne's meters in the UK?