A few other useful things about SSH aliases, especially w.r.t. not just using shell aliases:
They set you up with a layer of indirection that you can change later. Git-svn doesn't like having the URL to the SVN server changed, but if you set up a git alias to "svn" instead, when the SVN server moves for some reason you won't have to do anything except change the svn alias contents. You can also share the resulting tree between multiple people easily because they can plop in their own "svn" alias that uses their own user instead. In general you can safely reference the SSH alias in any number of places (beyond just shell scripts) and know that you can trivially change the alias later without having to change all those things.
There are many things that will use SSH, but won't accept any parameters, or will accept only a small subset. Emacs can use SSH to access remote file systems by opening "/ssh:username@ip:port:/file", but it will only take username, ip, and port (AFAIK). With SSH aliases, you have the full power of SSH available to you, so you can use all these other nifty things people are talking about. I've also been using ddd to remotely debug perl lately and that pretty much seems to demand 'ssh host' with passwordless login and nothing else.
They set you up with a layer of indirection that you can change later. Git-svn doesn't like having the URL to the SVN server changed, but if you set up a git alias to "svn" instead, when the SVN server moves for some reason you won't have to do anything except change the svn alias contents. You can also share the resulting tree between multiple people easily because they can plop in their own "svn" alias that uses their own user instead. In general you can safely reference the SSH alias in any number of places (beyond just shell scripts) and know that you can trivially change the alias later without having to change all those things.
There are many things that will use SSH, but won't accept any parameters, or will accept only a small subset. Emacs can use SSH to access remote file systems by opening "/ssh:username@ip:port:/file", but it will only take username, ip, and port (AFAIK). With SSH aliases, you have the full power of SSH available to you, so you can use all these other nifty things people are talking about. I've also been using ddd to remotely debug perl lately and that pretty much seems to demand 'ssh host' with passwordless login and nothing else.