I have been using the Python language to write various little hacks and applications for a year or so now and it has pretty much replaced every other language for me to do these tasks. It is just such a powerful and easy to use programming language.
However I would hardly put myself up there as an experienced Python programmer (still have Learning Python from O'Reilly within easy reach), so I was intriqued when I heard about a Python tutorial/puzzle website called Python Challenge. I have been working my way through the puzzles for some months now and have just this second solved Level 21.
Now I have decided to post solutions to puzzles I complete on this blog but I really really suggest you do not read these unless you are really stuck. I will be posting these solutions ROT13'ed, so you cannot 'accidently' read these solutions. I will also not be posting any source code (my Python programming is really untidy hacks). Again I recommend you post for help on the very good forums provided on the Python Challenge website before reading this, or even send private messages to other users on the forums (they are a pretty friendly and helpful bunch).
However for anybody still interested, here is the solution:

Lbh fgneg bs jvgu n svyr pnyyrq cnpxntr.cnpx. Guvf svyr unf orra pbzcerffrq ybgf naq ybgf bs gvzrf hfvat n pbzovangvba bs myvo naq om2. Lbh arrq gb qrpbzcerff guvf svyr hfvat rnpu bs gurfr yvoenevrf nf nccebcevngr (hfr bs n urk rqvgbe vf bs terng hfr urer). Xrrc n erpbeq bs ubj znal gvzrf lbh hfr gur myvo yvoenel va n ebj naq yvxrjvfr gur om2 yvoenel.
Nsgre n pregnva ahzore bs ehaf, lbh jvyy svaq gur svyr vf ab ybatre va rvgure sbezng. Guvf vf abg npghnyyl gur pnfr. Vs lbh hfr gur urk rqvgbe, lbh jvyy abgvpr gung gur svyr unf npghnyyl orra erirefrq, fb lbh jvyy arrq gb syvc vg naq vg jvyy orpbzr n myvo svyr ntnva. Abgr guvf syvc nf gur raq bs guvf frdhrapr.
Lbh jvyy unir gb ercrng gur nobir fgrcf n ynetr nzbhag bs gvzrf (cebonoyl orfg gb jevgr na nccyvpngvba gung qbrf nyy bs guvf sbe lbh nhgbzngvpnyyl) - whfg znxr fher lbh xrrc n abgr bs gurfr ahzoref bs qrpbzcerffvbaf.
Svanyyl lbh jvyy ernpu gur raq bs gur svyr, juvpu jvyy or vaqvpngrq ol gur grkg (va erirefr) 'Abj purpx lbhe ybtf'. Gur ybtf va dhrfgvba ner gurfr inyhrf lbh unir orra xrrcvat. Lbh abj arrq gb pbaireg gurfr inyhrf vagb n tencuvpny ercerfragngvba bs gur xrljbeq sbe gur arkg yriry. Abj nyy bs gur myvo qrpbzcerffvba inyhrf fgnaq sbe n ahzore bs 'Juvgr' ryrzragf naq gur om2 inyhrf sbe 'Oynpx' ryrzragf jvgu gur erirefrf vaqvpngrq gur raq bs gur yvar. V qvq guvf fgrc va n grkg rqvgbe hfvat fcnprf sbe gur 'Juvgrf' naq '#' sbe gur oynpxf. Bapr lbh unir qbar guvf, lbh fubhyq or noyr gb frr gur xrljbeq juvpu vf 'pbccre'.