Logology - Get a designer-quality logo for your startup in 5 minutes.
MilkDrop - 3D audio visualization plugin, compatible with WinAmp plugin API
LogoFreeway - Logo Creator / Logo Maker
projectM - projectM is an LGPL'ed reimplementation of Milkdrop under OpenGL.
My Brand New Logo - Create your own professionally designed logo in 30 seconds. For freelancers, start-ups and other companies.
Magic Music Visuals - Fully-customizable and highly responsive visuals for live and recorded audio & MIDI.