Installing apps onto external HDD ?

[Bern]

I have ordered an external FW800 enclosure for a spare 100GB HDD I have. I thought it would useful for installing apps onto that I don't use often thus saving some space on my MBP HDD. The question is what is the correct way to do this? Do I have to actually install OS X onto the external before I can install apps on it, as a friend suggested to me, or does my MBP recognise it as an extension?

[mad jew]

Nah, you don't have to install OSX onto it, although it may come in handy if ever you need to boot from another source. If possible though, I find it's just easier to keep 'em all in the Applications folder or wherever they're installed by default. As a rule of thumb, apps that don't have installers can simply be dragged to wherever you want them.