Need to be able to search for data, maps, and tools on ArcGISOnline by extent or location. I'm not interested in data if it doesn't cover the area I'm working in, and I don't want to have to wade through a lot of poorly described datasets to get to what I need.
Best case would be an interactive map as part of the search parameters so you could draw the area you're interested in. ArcGISOnline already stores extent as part of the details.
A nice addition, of course, would be that if you are getting data from Desktop, or ArcGIS.com or ArcGIS Explorer online, you could search from your current map extent.