Very powerful yet only 36K. Very fast, small enough to be attached to an email, requires no installation. Handles huge diagrams. Excellent for organisation diagrams, structure charts, layout plans, electrical circuit diagrams, any kind of line drawings. Exports to WMF, EMF, bitmap. Has to be seen to be believed.
Zip file contains quick tutorial.
2.43 MB Reptile is a cool application that lets you create funky backgrounds. Easily produce any combination of textures and backgrounds.