wow!
this is definately doable, after reading the documentation on phpBB3 integration.
the only thing right now question wise is:
1) standalone or integrated window?
2) smiley sharing
3) css sharing
4) actual shoutbox DB sharing (not sure if that's important)
5) integration into ubbt groups. ie: i might not want all of my mods to also be shoutbox mods.. so i'd create groups in ubbt like 'shoutbox mods', 'shoutbox admins' that are used instead.
6) flash + ruby implementation (i'd prefer this [server load and overall speed!], but it's the least probable install, because ruby ain't that popular yet) -- i'll prolly do 2 integrations.. a) standard php b) flash/ruby for teh geekz0rs
Good stuff zarzal