There seem to be lots of ways to contribute to the human database of knowledge as an amateur astronomer, which is one of the main reasons I am so keen on this pastime, alongside the fact that the skies are just so mesmerizingly touching. I have just discovered another:
Double Star measurements.
This involves measuring the separation and angles of double stars and submitting them, and/or peer reviewing other people's submissions. This all sounds very acceptable!
There is also photometry, which seems like a lot of hard work and difficult for amateurs (ie me) to contribute in relation to the others.
The other area I have seen is spectroscopy, which to me sounds like a perfect blend of astronomy, astrophysics and achievability. I love the idea of being able to find out crucial information about objects incomprehensibly far away, purely through the application of skill with your equipment and rainbows. Lovely, and this remains a big motivational factor to learn and master what is available to us humble amateurs. It's good to have a variety of short/medium and long term goals, and this one ranks high as a long-term biggie.
I feel I am nothing if not overconfident in my abilities involving something I am a rank beginner at, but if you don't aim high, you are never going to hit high.
If anyone knows other avenues to contribute to the fountain of human knowledge, please let me know. I started a thread about it: http://stargazerslounge.com/topic/219146-enlarging-the-noosphere/