Who knows how long we'll still be carrying wallets around, what with commerce-enabled cellphones and implantable RFID chips, but if you're hanging out in dark places that only take cash (we're talking about a bar, of course) and you want to avoid tipping a hundred dollar bill, Nate True's "Walluminate" light-up wallet may be just what you need . It's not for sale, and he doesn't provide any detailed plans (thought you can peep its debut here), but any self-respecting DIY-er should be able to figure out how to whip one up, using just a couple of LEDs and some miscellaneous electronic components.

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