Here's an iPhone tip for installing your own ringtones on 1.1.1 without having to jail break it. The details are in this blog entry, but the basics are as follows...

You'll need iPhuc, Ringtonator, and a text or plist editor. Then...

1. Prepare your ringtones. Iâ??ve only tried this with m4a files. Your mileage may vary. First, run your ringtone trough Ringtonator. You should now have both an m4a version, and an m4r version of your ringtone.
2. Load up iPhuc and add BOTH files (m4a and m4r) files to the /iTunes_Control » Ringtones directory. (using the putfile command).
3. You need to get the Ringtones.plist file from /iTunes_Control » iTunes using iPhuc and the getfile command. Save a copy of the file in case your make a mistake!
   
   Then youâ??ll need to edit the plist in the p...

I discovered that it is possible to type email, text messages, and enter text in most western languages. Simply tap and hold the button for the letter that most closely resembles the one you'd like to type. While holding the key down, an additional menu will appear where you can select the desired letter or accent.

For instance, to get an é, simply tap and hold E and select desired letter with accent from pop-up menu.

[robg adds: This feature was added with the iPhone 1.1.1 update, but as of now, it's not yet documented in the iPhone's user manual (which hasn't been updated for 1.1.1), nor anywhere that I can find on the iPhone support pages or even in the what's new video.]

Having used the iPhone for some testing, I saw that some SMSes corrupted the database file and the SMS app no longer worked. It would simply quit when I tried to open the SMS. The Apple suggested way to fix this problem would be to reset the iPhone by using the Settings » General » Reset » Erase all Content and Settings. But this would mean that you would have to resync your iPhone again. The easiest way I have found to do this is as follows.

1. Install iNdependence 1.2.2.
2. Install AppTap.
3. Download any Terminal app from within the AppTap installer on the iPhone.
4. Open the terminal app and enter these commands:

   $ bash
   $ rm Library/SMS/*

   Note that you will lose all your saved SMS messages.
5. Exit the terminal app.
6. Restart your iPhone.

Your SMS app should now be as good as new while all your othe...

If you're on another Mac and want to sync a song/video to your iPhone, iTunes will clear your Music/Video Library. But the iPhone syncs Podcasts separately from the Music/Video Library, which means you can use Atomic Parsley to rewrite some flags on your songs/videos, and iTunes will sync the song/video as Podcasts without touching your Music/Video Library.

So, grab Atomic Parsley, and run it with these modifiers (URL and GUID can't be blank):

... --podcastFlag true --podcastURL 'www.google.com' --podcastGUID '0000'

Now drag your song/video over to iTunes, and it'll show up as a Podcast and sync without touching your Library. Friendly note: The Podcast will show up by Artist metadata or podcastURL. This hint inspired by the methods covered in this one.