Yes, I do work on my web projects at work. How? I class and report my hours spend doing it as training on the job, and indeed, it often is.
I don't even have a job that involves webdev (mostly) but scripting is something I do. There have been occasions where I've written PHP script to do batch processing of stuff from the command line, I also have to handle SQL databases here so that mucking about with SQL is of course adding to my knowledge.
