10g tanks are possible, but they are quite limited. Probably the biggest drawback IMO is that a tank this small requires daily attention to replace evaporated water. We're only talking 5-10 minutes on the typical day, but it's not something that you can skip and let slide...if you go out of town for a few days, you can't expect the tank to be functional when you get back if you don't have someone caring for it.
The other significant limitation on a 10g is that you are best off sticking with a single 2-3" fish. You can't keep multiple fish in a 10g unless they are REALLY tiny, like 1" neon or clown gobies. You can fit a significant number of invertebrates into a 10g tank with some planning and money, but stay realistic and plan for only a single fish.
So, in short, it's do-able, but it's not ideal. If you have the space/money, go for a bigger setup.
