Having worked with gallium, it is not the easiest metal to work with. It forms oxides easily on its surface, and when these oxides combine with the metal, the metal can stick to metals and glass quite easily. Gallium has been used to back mirrors for that reason.
For those wondering, just because it melts easily, does not mean it has any vapors. Unlike mercury, it has a very high boiling points and has essentially zero vapor pressure at temperatures that can be tolerated by people. As for non-toxic, as far as I know it is not poisonous in reasonable quantities, but neither is it generally recognized as safe (GRAS). Six-nines gallium is probably what to use (99.9999%), as Five-nines gallium (99.999%) usually has signifcant mercury levels in the remaining portion.
It supercools very nicely in plastic containers, and once melted will stay liquid at room temperature for quite a while. It expands upon freezing, like water, and often develops a distinctive cracking pattern when solidifying.
It will eat aluminum instantly. Certain stainless steels are fine for a while, but iron (not plain steel), berylium, tungsten and the like are other metals you can use with it and not have problems with dissolving part of it.
It is a blast, and you can buy small quantities of it from Amazon.