Looks good Gadget, good heat sinking. I bet it can handle more than 3A, at least briefly. How much did it cost for all the parts? I spent $24 on mine just because I didn't want to bother with making one myself. People need to know it's easy to make these and cheap if you make it yourself.
Cost? Hmmm...I'd say it cost less than $9, looking at current prices of the parts and board material. I had a bunch of the parts already on-hand from scavenging dead electronics, though. Took about an hour to put together and solder up. MAN...those header pins are A BITCH to solder!! Kept melting the black plastic retainer! I finally said screw it and pulled the pins out individually to tin 'em. Anybody know a better way?
As for power, I've only had it up to ~2.4A. If I put a fan on it, it'll keep the smoke in for a minute or so, but I didn't linger there for very long as the N4005's are rated for less than half of that. The resistor is a 2W.