Photo Management

I am running into a problem. I have never been much of a picture taking kind of guy... that is, until I got a dog and a son. Now I am snapping pictures like a mad man with my Canon Xsi and amassing thousands of pictures named IMG_9321.jpg. I need help!!!!

I have my photos organized in a X:\[year]\[month]\[event] folder structure, but as time goes on I am forgetting what happened when. When my cat loving friends come over, I want to show them a picture of Wilson eating the neighbors cat, but I can never find it. (joke)

I had tried Picasa in the past and it looked promising. I am tempted to get the latest version and give it another shot, but I am wondering what my other options are. I did a little looking around and then started thinking... why not get a mac? Did I really just think that?

I will surely try the free Picasa before jumping ship and spending $2k plus on a macbook pro, but that macbook may come in handy for, say, trying .net development?