in reply to Back to Perl

Good luck. I've had the odd (well "odd" isn't the word, "miserable" is) Christmas or two like that. And had Perl as something to keep my mind off the bank statement etc..
Yes, algorithm stuff was useful, and I suppose it depends a bit on what sort of work you're used to doing. I found lots of document conversion stuff was handy for catching up with regexes, including new developments in regexes. But the other important point was to convert straight functional coding into various O-O styles --to re-acquaint with the object formats etc...
And exploring the depths of Parse-RecDescent was handy, too.
There's some bias there -- these are areas I work in or am interested in... but there's no harm in picking your own interest area...