well as i didn't know that people here are not familiar with these fonts ,i love my N900 as you guys do too , just sharing my love with this devise :P
well THIS IS NOT MY WORK .
(repeating) this is not my work , collected from an other forum
sharing it to let you guys to have more fun with your devise
p.s INSTRUCTIONS
you can use theme customizer to change the font but theme customizer dont change the font of menu icons and of the digits on lock screen and of the message written by the interal keyboard .
update :
you can select any font you wanted to.
just replace the orignal nokia fonts which are in the zipped file and then download any .ttf font you want
( courtesy : corduroysack ) you can download fonts from www.dafont.com and just simply place them in /usr/share/fonts and enjoy
well if the instructions are driving you crazy then you can leave other words in the instruction just follow this
to apply a different font you must reapply the nokia original font first, (there included here) and reboot phone,
then apply your font files and reboot
n900 support two types of formats i guess.
one is .ttf and dont know about the other one.
so try to find .ttf format fonts and place them in usr/share/fonts/nokia
and use theme customizer to change the fonts.
that's what i have tried with one font .
hope it will work for you.
p.s i am not a coder or dev so please if it wont work dont get mad at me :P