I actually use apt-get to install it at first, which gives me boot scripts. At least on Debian, you can apt-get remove it and the init scripts will still be there. Meaning, I don't have to go find one on the internet. Might not work outside of debian :)
I dont know, I compile from source the issue is that modules have to be compiled at runtime and everyone needs different sets, so there is rarely a PPA with what you want unless you build your own.
Its a build model that does not work so well with binary package managers, works better with say the Gentoo use flag model.
Oh and if you are not using any nginx modules you are missing out on a lot of its power, you should be able to move big chunks of your app like auth right into nginx, use redis and memcache directly, and so on.
I recommend against doing this on Ubuntu Lucid without first installing the unofficial nginx PPA, unless you want to get stuck with v0.7.65.