I use a tickle file regularly and like it. I tried it years ago pre-GTD and it didn't work, but with GTD it works. For me, two keys to making it work are:
-- I use David Allen's rule for calendars, which is don't put something in there just because you don't have time to do it now. This keeps pulling things out of the tickle file much more pleasant. and
-- I made sure there was almost always at least one item in each folder, so I wouldn't be bored by having to look in empty folders. At first, I made up things to add for fun, such as a reminder to sing over a song I'm memorizing. Pretty soon, though, there were enough things in there that eventually I shifted some categories of things into a different system.
I put lots of little things in my tickle file, like reminders to water my plants, charge a cell phone or bring something with me. I generally don't file things in there: I pretty much only put my own handwritten reminders, not things I might possibly want to search for later.
I do lots of things on the computer, but I like to have my tickle file and some of my other systems on paper.
People with fewer things to put in might consider a one-folder-a-week or one-folder-a-month tickle file.
Jesig, if you don't have room for a big filebox, you might consider a little box of index cards, or just a pile of index cards with an elastic band around them, as a tickle file; but it sounds as if you're happy with an electronic solution anyway.