Before Apple released iTunes 10 you could easily search through your installed apps in the device menu under apps. But now that search form is gone in iTunes 10.
Now you can simply use the main search box located in the top right corner of iTunes as demonstrated in this screen shot:
You can do the same with Music as well. Not podcasts or TV shows though.
And I believe this is new to iTunes 10 as well: you can drag an app from the apps list in iTunes to a device to install it:
Do you have any iTunes tips? Feel free to share in the comments.
Arabic version of this post on SaudiMac Arabic Edition.