No .bash_profile in OS X Lion? I just did a clean install of OS X Lion and I see that now I have no .bash_profile file in my home directory.

Should I create this by hand? (I want to save in it some alias.)

Thank you.

PS : The only file that exist now that I could use is /etc/profile
By default this file does not exist on any version of OS X. And yes, it is up to you to create it manually:

touch ~/.bash_profile

Alternatively, you could use nano as well if you want to edit the file at the same time:

nano ~/.bash_profile

Do not monkey in /etc unless you know what you're doing.