When I went to start my knit bag for my sock pal, I realized that I didn't have any 6mm Addis (that I could find). I dug into my knitting needle bag, and pulled out my "cheapo" straight needles. After knitting a few rows, these needles were driving me nuts, because they were too long.
I solved the problem by cutting them to the right length, and making knob-type things with duct tape. Surprisingly, the yarn has not gotten stuck to the tape, and they are the perfect length.