I don't think it's a good idea. Tomboy is a freaky fat thing, because it's based on mono. Just look at the list of dependencies: http://pastebin.com/RbGXpTs1
I was aware of this mono controversy to a degree. Would porting something like Gnote or Zim be a suitable alternative? I would really like to have some kind of note taking application that I'm able to synchronise across my PCs. That's another thing, Dropbox, this was ported to the n900 also. Any chance of this living on the Pandora?
Just throwing things out there, but thanks for any responses.