My room is PACKED full of various activities. I try each year to organize them by skill but we often go back to the old tried and true and don't get around to using all the neat hands-on stuff that is in the room. I once tried to create an inventory but this proved to be difficult as some of the activities have such similar names that you don't really know which is which from looking at the activities.
This year I decided that I woud approach this a bit differently. Its taking some up-front work but its starting to work out really well and I'm excited. What I'm doing is taking pictures of every activity/program that we have in the room. I'm printing them off as photos and typing up any information about those activities that I think is necessary and gluing that to the back. Then I'm taking photo boxes and sorting them by type of skill. If something fits in more than one skill, I'm putting it in there. I'm planning to expand this over time to be a little more detailed than what I'm doing right now (for example: taking pictures of each inteactive book and putting it where it belongs rather than just interactive books in general).
What this is to achieve is that I will have a real inventory of what is in the room but it will also make it easier for me when I know a student is going to work on a specific skill as I can just go to the section for that skill in the box and then pull out the cards and decide which activites would be appropriate for that child.
When I get or make new activities, I will add them to these boxes.
As a fun aside, I have been working on my small activities right now and if you would like to see the photos that I've gathered so far, here is a link to the album with them: http://redlights.typepad.com/photos/classroom_activities/