Apple has released iPhone OS 2.0.1 for the first-generation iPhone, iPhone 3G and iPod Touch. The new release resolves several performance-related issues and bugs found in OS 2.0, though you wouldn't know it from Apple's paltry release notes, which state only that the update includes "bug fixes".

Among the improvements we've noted so far:

• Better keyboard responsiveness
• Less lag in the Contacts application
• Faster backups

You can obtain OS 2.0.1 by connecting your iPhone to a host computer, launching iTunes, and clicking the "Update" button in the device pane. Alternatively, you can manually download the update via these links for the first-generation iPhone and the iPhone 3G. The iPod Touch update must be downloaded via the iTunes "Update" button because it is a protected asset.

If you used one of the aforementioned manual downloads, hold the option key under Mac OS X or the Shift key under Windows while clicking the "Restore" button in Windows, then select the downloaded file.

Problems applying the update if you received an error -19 or a different message that prevents the update from taking place, try turning off automatic syncing, then quit iTunes and disconnect your phone. Launch iTunes again, wait for it to find your phone, and try the update again. Failing that, try the tips in this Knowledge Base article.