Don't think act

Available at Mesmerik

Don't Think Feel

Or use a balanced combination of both!

Nice single line continuous type, available at hoimi.jp

Think Forward - Look Back

“the longer you look back, the farther you can look forward.”

Great tee design by Mymutas available at Origin68.

Think, Care, Act, Save Darfur

Noble cause. It's a shame we hear so little about it in Holland. Supposedly available through the Urban Outfitters webshop, although I could not find out where. Found the tee at schemamag.ca.

Machines should work people should think

IBM Pollyanna principle, found at superlocal's Flickr photostream.