So you've downloaded, perhaps even purchased, some of the new iPhone/iPod touch apps from the App Store. Then you discovered you don't really want or need that app. This tutorial will guide you in deleting it from your iPhone or iPod touch. Hey its easy to delete apps from you iPhone, just follow these steps:

1. On the springboard, locate the app you want to delete.
2. Tap and hold down the icon of the application you want to delete. After a few seconds your screen will start to "wiggle" and an X will appear next to each of the apps you've installed via the App Store.
3. Tap the "x" next to the icon of the app you want to remove. When prompted, select "Delete".
   
4. Poof !!! And now it's gone.
5. If the application is listed in your iTunes Applications as well, you'll want to remove it from there - or else it will re-install the next time you sync. Alternately you can keep the app in your iTunes Applications, and set iTunes not to sync all applications, just the ones you want to keep. See the Applications tab of your device the next time it's connected in iTunes for syncing options.

Related: Here is a tutorial on how to delete many Apple apps from iPhone at one time.

how do I get them back? Do I have to restore?

OK, the good news is you need not restore your iPhone or iPod touch to get your apps back. All you have to do is power the iPhone or iPod touch off (hold the sleep button on top of the iPhone or iPod touch until the "Slide to Power Off" message appears, turn it off, then turn it back on (pressing the same button). All the banished official Apple apps will reappear back on the first available open apps slots on your iPhone or iPod touch. The only caveat would be if you had a full 148 apps on your iPhone or iPod touch, and no open slots for them to return into, in which case you'd need to delete a few apps and power off/on the iPhone or iPod touch to get them back. A sync in iTunes will also bring them back.