The next best thing for Nokia N900 is the Community SSU, also known as the Seamless Software Update coming from the Maemo Developer Community since Nokia has no longer official support for the device/platform.
In case you have the last update of Nokia Fremantle, PR 1.3 (20.2010.36-2) in your device, simply go to j.mp/communityssu (shorter address for the above mentioned site) with the browser of N900 and click on the “testing” icon at the top right area of the page. This will add an Application Catalogue called Community SSU (testing) to the Application Manager and install the Maemo 5 Community SSU enabler.
Practically you just need to accept/ok everything that comes up. Same is described in the Maemo Wiki.
Another thing worth of trying is the MeeGo Handset version for N900.
A recent of MeeGo build for N900 can be found from the MeeGo Builds repository at Maemo.org, under corresponding directory, depending which version you are after. Unfortunately the meego-handset-armv7hl-n900 build does not succeed every week, so you might need to go through few different version directories to find a suitable image. At the time of writing, 184.108.40.206.12.20110810.2.DE.2011-08-29.1 is the most recent build and like the name suggest, made in 29th August 2011.
Installation to N900 goes in similar fashion as previously described, you just need to download two files, uncompressing the first one:
- mg-handset-armv7nhl-n900-ce-stable-220.127.116.11.12.20110810.2.DE.2011-08-29.1-mmcblk0p.raw.bz2, ~443 MB, uncompressed ~3.55 GB
- mg-handset-armv7nhl-n900-ce-stable-18.104.22.168.12.20110810.2.DE.2011-08-29.1-vmlinuz-2.6.37-24.6.CE-adaptation-n900, ~2 MB
After running the raw writing command with dd, the output should be something similar to:
7454720+1 records in 7454720+1 records out
Since MeeGo is still by far in the development state, thus not very usable for the average user, please consider testing it with the memory card option. That is, data written to microSD card, kernel booted to memory with a flasher. A slightly more permanent solution is to use uboot-pr13 from Extras-devel catalogue or BootMenu from Extras catalogue.