Not really a development thing, but whatever…
Everyone who uses Linux on the command line will hit this one at one point or another – You ‘cat’ something, discover it’s a binary file, then discover it’s completely fucked your terminal, thus:

Not so very long ago I used to close and restart the terminal, for I am very, very lazy. Then I discovered what the fix was because I am awesome.
There are two solutions to this problem:
1. Use the ‘reset” shell command
% reset [return]
OR
2. Issue the following set of commands (working blind)
% cat [return]
% [ctrl o] [return]
% [ctrl d] [return]
Shazzam:

Just for the record, if you feel like breaking it again, run the same set of commands listed above, replacing Ctrl-o with Ctrl-n