Also rather than 'plugins' per se you might find more useful stuff googling "photoshop pixel art actions"
Slightly off-topic but some people might find it useful re: retro/pixel image converters: HyperDither is a standalone free OS X utility recreating Bill Atkinson's truely beautiful black and white dithering algorithm from HyperCard: http://www.tinrocket.com/hyperdither/
That's actually really cool.
Convert photograph to pixel art instantly
image to pixel art converter
convert ascii art to pixel art
convert pixel art to ascii art
retro game fonts
Automatic NES palette color limiter filter
magically turn any digital photograph to pixel art
Instant Gameboy camera filter
instant Amiga filter
instant NES filter
instant 8bit filter
double the size of pixels filter
instant 16bit filter
instant 32bit filter
instant 256 colors filter
instant 16 colors filter
Thx
Converters (photo->pixelart) usually make really awful looking stuff and probably wont be even considered as pixel art. This is not recommended.
I use some conversion techniques in PS sometimes, but they always need more work in the pixel level.
lol fakebit