This nifty program performs batch conversions of programs from a wide variety of types, including JPEG, BMP, TIF, PNG, and the usual other suspects. Lots of other features are added to the mix, including such goodies as watermark insertion, cropping, sharpening, blurring, etc.

Version 3.0 shipped in April, 2003.

http://www.reasoft.com/products/reaconverter/