I have made some significant progress in organizing myself with org-mode (basically a really well thought out emacs outliner) - consider this a plug :).
Now I think I am ready to bite the bullet and automate another part of my mental apparatus, memorization. I'd like to hear other people's experiences with SRS - spaced repetition - (negative, too), what software they use, what do they use it for, how much time they spend. I expect these to vary, so stating your reasons is worth an extra upvote (and thanks ahead)
ETA: When do you decide something is worth memorizing vs. putting it into a searchable database?
(I have a todo somewhere in my org files about writing up all my Anki experience in a nice comprehensive article. One day I'm gonna get to it.)
tl;dr: Use Anki, read its FAQ, keep it simple, always do your reps.
I love my SRS. Without it, I would have failed classes, would never have gotten anywhere with Japanese, could never handle my high book throughput without forgetting them all again. Anki and emacs are easily my two most important tools. I don't consider a topic understood until I have written a short outline in org-mode and put my notes into Anki.
A few general points.
I highly recommend using one big deck for everything (full argument). Keep cards simple and keep all the context you need to answer them on there. A card should essentially ask you for exactly one bit of information - as little as you can get away with. Some redundancy among cards is useful, too. In general, Supermemo's 20 rules of formulating knowledge are key.
Keep your sessions short. I'd recommend timeboxes of maybe 10-15 minutes. If you can spread your reps through your day (by using the Iphone app or whatever), do that. I like doing them on the train.
When in doubt, delete. If a card feels wrong, boring or sucks up your energy, throw it out. If the point is important, suspend it and look it over in a few days. Maybe redo the card. But mostly just throw it out and if it matters, you'll add it back in time anyway. Long-term success is more about managing your energy and motivation than individual cards. If you start dreading your reps, you lost.
Use your SRS for everything you wanna remember. I use it for languages, math problems, important points from books, personal insights, emacs hotkeys and so on. There's really no topic that can't benefit from memorization. (Of course, only remember things you care about. This may change over time, so delete away.)
Also, don't cheat. What I mean is, don't add cards about things you don't really understand or answer them too optimistically (as in "correct" after you took 30 seconds). You'll only screw yourself over. I'm not sure if this is a common problem, but I made that mistake early on, so yeah. Just because you can add hundreds of pre-made cards before properly having studied the topic doesn't mean you should. Your reps should be fast and easy. A few seconds, an effortless answer, next. Anything else gets a "fail" or "delete".
I check my success rate and consistency with daily reps as a sign of health. If I drop below 80% retention rate for normal cards (90% for old ones), then my cards are either boring or I'm adding them too early (i.e. before I really understood them). If I stop doing daily reps, then something is sucking away my energy. I typically fix this by limiting the most draining topic and adding more "fun" cards (mostly questions about books I'm reading or trivia).
Personally, I currently have a deck of about 1500 cards with something like 50-100 reps a day. I delete often and have gone through somewhere between 5-10k cards over the last 2 years or so. Something like <100 reps/day and at most 20 new cards/day is my sweet spot. I can theoretically go up to 1000 reps a day (takes about 2 hours and a few cups of coffee), but then I'm useless for the rest of the day (and enter mania due to the coffee). Intentionally doing less than your maximum so you don't exhaust yourself is crucial.
Should you be interested in languages or list-like material (poems, lyrics, digits of π, ...), then I can add a few specific tips. Generally speaking, Anki's mailing list and plugins address virtually any problem you might encounter.
When studying for exams, I've had moderate success with adding e.g. algorithms or formulas before I understood them. On the first time when they come up, I don't even try to recall them, but instead look at the answer, try to figure out how it works, and then mark it as failed.
Say it was an algorithm. When the card comes up the next time, during the same day, I let myself mark it as correct if I... (read more)