Here's a very interesting idea to help birds see glass windows yet not obstruct our view.
Ottawa boy's invisible invention warns birds about deadly windows
For his latest school science fair project he has invented invisible warning signals that can be placed — discreetly — right in the middle of a window pane. Read more:http://www.cbc.ca/consumer/story/2009/01/21/ot-090121-bird-decals.html
Further research turned up that this product is already available--news to me. http://windowalert.com/
However, I like the idea that you can just go buy the glow paint and make your own!