Russell mentions Cheshire eyepieces - pretty much same thing as your homemade collimation cap, but on steroids. You can achieve all your collimation needs with it, but is a pain in the neck when you are way down at the primary mirror end of the scope, and you need to give your attention to the top. This is where a laser device is a good tool to have. Yes there are some problematic laser devices out there, but the short comings are easy to overcome. You might like to have a look at this following thread I started on tricking up a humble GSO laser collimation tool:
http://www.iceinspace.com.au/forum/s...ser+collimator
While this GSO collimation tool has short comings, it is a good and inexpensive way to start laser collimation. Just need a little TLC with it and it will be humming.
The main advantage of a cheshire, and you colli' cap too, is it will deal with the collimation of the secondary to the focuser where a laser won't.
Like Russell, I too use a laser and a cheshire eyepiece for my Newtonians