Long-time Letterology fan Rob Bowker of Typewriter Heaven, home of the Type-o-Matic, sent me this lettres trouvées link today which gave me a good laugh. He stumbled on this cap H on what passes for a hill in his part of the Typosphere. It could be an H for Hazard, or for Hill as he suggests. Or maybe it's just a minimalist concrete poem.
Bowker can frequently be found test-driving one of his many typewriters and tasting local beers (is this legal?) Occasionally he will post some great typewriter ephemera such as this recent gem he entitles Magic Fingers. It is a keyboard template from a Halda Portable Typewriter owner's manual.
Bowker recently shared some of his own keyboard handiwork at Typewriter Heaven, which he calls Spiralcast. It's a story about belt-driven turntables and typing, but I think it qualifies as a concrete poem. Since Bowker happens to be a member of The Society for the Ethical Treatment of Typewriters, I trust he wasn't drinking and driving when he put his Olivetti Lettera 32 through all of the tight curves. I can't even read it without getting dizzy.