What should I get my pen pal for his B-Day?

I've been writing a guy I've never met for 5 months now. I don't know if he likes me, but his last letter was 15 pages hand written in his perfect, tiny handwriting, and he gave me two pictures of himself with it. (Not the first time I've seen a pic of him. Or him of me. BTW, he's hot!) Also, he's drawing every letter of my 20 letter name in an ornate design and sending them to me one in each letter. But he's never said he wants to meet me when he get's back in Aug, or anything. He signs his letters, "Your Friend....." His birthday is the 20th. He like physics (a gyroscope? or is that corny?) outdoor activities, hammocks, electronics, writing novels, and especially mountain biking. Should I send him anything at all? Would he get the wrong idea and be weirded out and stop writing? Would he guess that I like him? Or is it just a friendly gesture? Help! Letter writing is so different from face to face!