IconEdit32 & IconJack32 (www.zdnet.com and search)
The only fully featured icon editing programs available for nowt in the public domain, as far as I can see. Grab and catalogue icons with IconJack, and edit them in multiple depths with IconEdit. A fantastic pair of common-sense applications.Splitz! (www.b-zone.de)
Slice & dice images into multiple JPEGs with automatically generated HTML code to glue them back together again. Facilitates rapid creation of professional webpages.XnView (freeware, www.xnview.com)
Graphics viewer which recognises a prodigious number of formats. Very fast, and can also apply various effects and filters, and batch process files. Invaluable!