The N97 Classic has just received an update in the form of a the v22.0.110 firmware. The update is a 4.9 MB download over the air and the new firmware will soon also be available via the Nokia Software Updater. In addition to bug fixes and general speed improvements, v22 comes with Ovi Maps 3.3 pre-loaded so you don’t need to install it separately if you want free navigation. This saves you a good 9-10 MB of precious phone memory, but if you choose to update to the 3.4 version of Ovi Maps, you’ll again loose the free space you just gained.
The update also brings RAM optimizations and according to Steve over at AAS after a fresh install (firmware update + format) you will have 55MB free on disk C: and almost 60MB of free RAM at first boot. I’d recommend giving your N97 a fresh start, so to format it you can enter *#7370# in the dialer and follow the prompts, this will wipe the entire phone memory so its prudent to take a backup.
If you are in for the finer details that a changelog brings, you might want to check this post by Norman over at Symbian World.