Nokia released its second update of the week for the Nokia N900 yesterday, with the release of the 2.2009.51-1 firmware update. The latest firmware – also known as PR1.1, follows on from updates to the Maemo 5 operating system on Tuesday. This time it’s a huge update, however, with a raft of changes in store. To find out what the new firmware has to offer, read on after the jump…

The PR1.1 firmware update for the Nokia N900 is available over the air (OTA), or can also be downloaded to your computer using Nokia Software Update (NSU), and installed when syncing. If you don’t have an unlimited data contract for your Nokia N900, make sure you connect using Wi-Fi if you opt for OTA, as the download is a not insubstantial 85MB.

Read our full Nokia N900 Review

It’ll be worth it, however, as it brings wholesale changes to the Nokia N900, the most notable of which being the ability to use the handset in portrait mode. Ovi maps is also updated, according to software website Soft Sailor, along with support for SIM cards on network provide 3, compatibility with Microsoft Exchange 2003, and an updated web browser.

Soft Sailor also notes that there are a host of other features and tweaks available in the update, but doesn’t point out what they are. As always though, make sure all your files are backed up before installing the update.

Have you installed the latest firmware for your Nokia N900? Let us know what else it has to offer.