This is, of course, not a novel idea, but I haven't seen it done much. Some distros support installing software with multiple package managers and I know that this is, to a point, possible on all distros, but it is usually that only one package manager is a default and recommended and using anything else implies a level of risk of breaking something.

I've been talking a bit with a_thing about this in #nuxified IRC channel. I find yum to be quite slow. Not only does it apparently update the package database every time it is ran (which even on slower broadband networks can annoyingly slow down the overall install process), but calculating dependancies takes a bit longer than I'd like.

I am trying to install the tango theme through portage but it just isnt happening. I am having problems with maskings. It asks for one to be unmasked, so I do, then it asks for another.
eg
I do
[code:1]echo "=x11-themes/tango-icon-theme-0.7.1 ~*" >> /etc/portage/package.keywords

Does anyone know of a tool that can convert slackware tgz packages into Archs pacman pkg.tar.gz packages?

I think that should well be possible considering that tgz packs are very similar in nature to pkg.tar.gz, that is, both are basically just compressed and archived binaries.

What do you use for package manager on slackware? Do you use any? Which one would you say is best and works most seamlessly with slackware (except installpkg of course)?

There seem to be quiet a few of them now like slapt-get, swaret and even smart. Last time I tried slapt-get it was really slow to download just the package database.. it just didn't work so nice as apt-get on ubuntu (and of course other debian distros).