One of the most frustrating times in paintball is when you've started a game, believing you have enough air, only to run out midway through the game. I'm sure most paintball players have heard the rata-tat-tat of a blowback gun that just doesn't have quite enough air left to recock or you've been firing your electro only to watch your paintballs start to plop only about twenty feet out of the barrel. To avoid this problem I long ago grew accustomed to using big tanks - usually a hulking 88cu 4500psi compressed air tank. I used a remote for a while, but I generally just screw a big tank onto my gun and head to the field. The added weight really isn't very noticeable, but the increased size definitely is felt every time I need to make a tight shot. It's not desirable, but at least I'm not leaving the field in the middle of a game.

Recently, though, I've started to develop a fetish for compactness. I'm much more at risk to run out of air during a game, but, depending on what I'm playing, the smaller size is worth that risk.

There are two ways to achieve a smaller size which I find quite appealing - use a 45cu compressed air tank or return to using CO2. As you can see from the picture, a 45cu tank is dwarfed by an 88cu, but it can still provide up to a thousand shots with an efficient gun. Alternatively, if you really want to go small and light, a basic blowback gun with a small CO2 tank and a simple hopper can't be beat. Before I snapped it in half, I used to put a 9oz tank and a gravity hopper on a Spyder Sport - it wasn't very accurate, but it hardly weighed a thing.

If you've never tried to go small, you just might want to consider a downsizing. You may not ever want to go back.
_{(Photo © 2008 David Muhlestein licensed to About.com, Inc.)}