Posted to RT (and mentioned on the internals list) a few smallish projects that could probably be tackled by someone looking to do some PIR work. Within 30 minutes, Klaas-Jan Stol had already started working on it. We now have a working [flush], at least for the most part. Thanks, KJ.
Talked to Donal Fellows on #tcl on freenode this week. We talked briefly about if any of tcl's builtins were implementable in terms of other builtins, which led to his posting at http://wiki.tcl.tk/15051
Having someone actually *implement* these for inclusion in partcl would allow us to reduce the amount of work necessary to pass more of tcl's test suite. (And, of course, for any other tcl implementors that aren't core-tcl).