Moss is awesome! And simple to keep alive even if you travel.
Moss had its heyday back at the turn of the last century when both the US and the UK had their own bryological societies and people built mosseries into their homes where they could enjoy the greenery year round. It's simple to build a mini-mossery, or mossarium, in your own home.
– a jar with a lid, this is a great use for stinky former-candle jars that you can't put food in
– water with activated charcoal [you can get an aquarium filter cartridge and split it apart and save the charcoal, add a few grains to your water]
– Spanish moss for drainage [available at craft or garden shops]
– MOSS [with some dirt on the bottom of it]
– frippery, to taste
Assembly is straightforward. Put rocks in the bottom of your jar. Pour in small amount of charcoal water. Put Spanish moss on top of it. Add moss. Add frippery such as birch bark, flowers, twigs, pinecones, ceramic frogs. Put the lid on. Put it somewhere out of direct sunlight. Add a tablespoon of water every few months if it looks like it's getting dry.
More mosstalk at lifehacker and this steampunk forum thread. For help with moss identifcation, read The British moss-flora (1905) or The moss flora of New York City and vicinity. (1911) You might also enjoy this moss poem from 1860.