The TM20 has since been replaced by the Panasonic HDC-TM55, but here's what we said about it when it came out:
The TM20 offers excellent full-HD video quality in a small package. Like its big brother, the TM300, it records to either a built-in flash memory drive (16 GB on this model) or a SDHC card slot so space is never an issue. The image stabilization is excellent as well, and works nicely with the 16x optical zoom. Despite a few design flaws, it's a strong buy, though we recommend that you save a few dollars and go with the similar—and more popular--TM10.