Fraps is a great software, but using it kicks my ASS. I have an AMD Athlon II X2 220 processor and 8 GB of RAM, which gets driven through my loving desk when recording with Fraps. It also doesn't help that the file size takes up 1 GB of hard drive space for every 7.5 seconds of a recording.
I like Fraps, but I wish there was an official portable version.