One thing that has always annoyed me about looking at the Apps section of iTunes -- where I can see the collection of programs installed on my iPhone (and now iPad) -- is that it took forever to load and display the icons for 500+ apps.
Then, while exploring iTunes 9.1 for new features, I noticed that the View menu works when in the Apps category. To solve the speed issue, just select the Apps category, then choose View » As List (or just press Command-Option-3). No more delays, and there's even a bonus to using this method: you can add additional columns to the display (by Control-clicking on the header area of the display). I added Purchase Date, Kind, and Version. (Kind is very useful, as it's the only way I know of to find the iPad-only apps in your collection.)
I will admit I have no idea if this is new in 9.1 or not -- I just know that I've not seen it before, nor had a number of fellow Mac authors and Twitter followers. Hence, it's now a hint.
Mac OS X Hints
http://hints.macworld.com/article.php?story=2010040418282265