Net Nanny for iPod Touch, iPhone, and iPad will be here in March. 

And in addition to installing Net Nanny to replace the Safari browser, take advantage of Apple's built-in parental controls features to set other boundaries for your child's device use.  
 
You can do any of the following on the iPod Touch, iPhone, or iPad: 

1. Disable Safari as the browser (because Safari does not filter web content). In March, get Net Nanny for iOS from the iTunes Store. If you disable Safari and install Net Nanny, you should disable the installation of new apps so Safari can't be re-installed (see #5 below).
2. Disable YouTube -- to prevent unrestricted access to videos, including those that are inappropriate.
3. Disable iTunes -- to keep costs down or to reduce access to apps and media (music, podcasts, tv shows, movies, etc.)
4. Disable "In-App Purchases" to ensure a child's use of a gaming app doesn't hit your credit card for unwanted charges.
5. Disable the installation of new apps, which allows you to screen the types of apps used--your child would have to get your permission to unlock that restriction (assuming you use a password).  To see how to set a passcode, keep reading.
6. Configure age-appropriate settings for Music & Podcasts, Movies, TV Shows, and Apps for your child. (see below)

To access these features, do the following:

1. From your device, go to Settings > General > Restrictions
2. Press [Enable Restrictions] and enter a 4-digit password. A password is needed to change or remove restrictions later. Don't use a passcode your child knows.  
3. Under the [Allow:] section, tap Safari to OFF.  This disables Safari as the browser.  Safari does not filter Internet content. Disable YouTube or iTunes here. You can disable the installation of new apps, which would allow a parent to screen the types of apps to be used because a child has to get permission from a parent to remove that restriction.  You could also tap off "In-App Purchases" to ensure a malicious app or gaming app doesn't hit your credit card for charges you don't want. 

To prevent your child from deleting apps, go to Settings > General > Restrictions > tap OFF for Deleting Apps. This action prevents your child from deleting Net Nanny, for example. 
 
Finally, under the [Allowed Content:] section, you can set age-level appropriate settings for Music & Podcasts, Movies, TV Shows, and Apps.  For example, for "Apps," you should consider setting it at "12+" or less.