This is quite rough at the moment, but I have compiled a statically-linked version of Opkg for armv5tel-compatible devices, which I believe includes most Android phones. So far, I have successfully installed packages from files and from repositories, and I'm still evaluating the possibility of using Opkg to maintain all sorts of things on the phone.
Opkg is a package manager not unlike Debian's dpkg/apt system. With this tool, we could easily install software from third-party repositories and keep it up-to-date. For now, there are some barriers against deploying Opkg on phones. Firstly, there are almost no Opkg packages for Android phones (though I do have some in my personal repository). Secondly, there is no GUI, and everyone loves shiny graphics. But I think these problems can be overcome, since Opkg is a pretty awesome little tool.
I posted this for a couple of reasons (other than to promote the use of Opkg on Android). So far, I know it works with HTC Dream and HTC Hero on CyanogenMod, but I'd like to know how it works on other types of phones if possible. I'd also like ideas and suggestions. Are there any Android developers or end-users out there who are interested in trying Opkg?
Anyhow, here're the links: [more info] [how to make a package] [how to make a repository] [downloads]
If you want to build it yourself, go ahead and knock yourself out ;p
Thanks for your time!