Can I install Android on my non-Android device?
Is it possible to install Android on an Ipaq rx1950?
And in general, what is the process of installing android
on different gadgets?
In general, installing an OS to a new platform involves writing a compiler for the processor architecture, writing the drivers, finding a way to write to a bootable storage and booting the new OS.
Nowadays, the first step (writing a compiler) is usually unnecessary since the free GNU Compiler Collection (GCC) supports nearly every processor architecture that you care about.
In many cases, the second step (writing drivers) can be leveraged since Linux kernel have drivers for many hardware configurations and Google and some manufacturers releases their driver to the open source. On some really esoteric hardware though, you might need to write your own drivers (this is often difficult since such esoteric hardware usually comes with little or no publicly available documentation). It usually helps if a device is popular, since that will increase the number of potential developers that are willing to spend their time writing drivers.
On regular computer architecture, you usually have privilege to write anything anywhere on the primary storage and full privilege on configuring the bootloader; but on mobile devices, the third step and fourth step (writing the OS to a bootable storage and booting it) may involve finding a security hole in the currently running OS since such devices often locks down the bootloader.