distro question

I'm looking for a small distro that will run off a USB stick in whatever the not-Live mode is called, the mode where files on the stick are modified as though it was a regular device. So far the ones that look like candidates are Damn Small Linux and Knoppix, but I haven't played with either one yet. I need to be able to install php-cli on the stick and will be using it as a backup mechanism. Some kind of "window manager" would be useful but graphics-mode GUI is not necessary. Comments? (Oh yeah, I'm a newbie, started using Ubuntu about a month ago, so apologies if this is a stupid question.)
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