I find it quite handy, I don't know about the legal issues though.
Also, I don't know if you've seen this, but it's a nice collection all in one .rar file
Trillian is on there, so I still don't know about legal issues
Unless Opera USB has Opera's permission (which they may) the distro is illegal. TheInfoBox's may be legal if Trillian isn't already "installed" (I believe you have to use Trillian's installer so the user is forced to click AGREE for their legal agreement)
Sometimes, the impossible can become possible, if you're awesome!
Trillian is already installed.