Exercism Foo
Started using Exercism about 18 months ago to learn some Golang and then stopped, cuz ... SQUIRREL.
Finally back at it, but now practicing with Ruby because I've been writing a lot more Ruby than anything else as of late, thanks to Chef. Still wildly curious about Go though so expect to get back to that when time permits.
For those who've not tried Exercism, I can't recommend it highly enough. Seriously, these problems will keep/make your brain sharp and sorta feel like a coder's equivalent to the morning crossword puzzle... or maybe that's just me.