Tweet backup recipe: This logs all your tweets to an ifttt/twitter/twitter.txt file in your Dropbox.
I’ve been using Tweet Nest for as long as I can remember, and it’s great, but it does require you to provide it a MySQL database, and is probably overkill for most people, including me.
This IFTTT recipe is nearly perfect in that its output is simply a plain text file, which is infinitely searchable and future-proof. Even if you moved to a new system in the future, that new system would simply have to be able to append to a plain text file; it wouldn’t even matter if the structure of the data was slightly different, as it would be searchable regardless.
(Remember, as with all of this stuff, you’re limited to Twitter’s 3200-tweet API limit, so the sooner you start archiving your tweets, the better.)