Here's an idea that steals from Star Wars a little. The idea of multiple states of 'Space'<P>For the most part, we all exist in Regular Space, where Time and Space are at a fixed ratio. I.E It takes X amount of time to Travel Y amount depending on speeds less than relatavistic.<P>There also exists two other states of 'Space'. First is UnderSpace, where Space is expanded exponentially in relation to Time. Therefore any travel done in UnderSpace will take many times what it would take in Regular Space. The only difference is, Entropy is also affected. So even though you spend centuries travelling a distance that would normally take only years or decades, you have not aged at all. However, everyone else in Regular Space has suffered those centuries which you spent travelling. It's inefficient, but a great way to capitalize on bank investments.<P>On the opposite side is HyperSpace. Here, Space is greatly compressed, but Time is greatly expanded. Thus travel can be achieved neigh-instantaneously, but the Entropic effects on organics would be tremendous. (A trip of only a few days would age you decades)<P>Now, to prevent such travel from killing its occupants, one could use a Statis system which preserves the occupants while they travel in HyperSpace. Under such conditions, the Entropic effects of HyperSpace are reduced below even those of Regular Space (Therefore, you age even slower than normal because your entire body is in Stasis). Such a system makes it possible to span incredible distances in a very short amount of time, without adverse effects on the occupants of the vessels in question.<P>It also sounds really nifty, even if it is mumbo-jumbo bullshit that I just made up. So there you go, all ships are equipped with a HyperSpace engine and all occupants can be cryogenically frozen while they travel. Almost immediately after they debark from HyperSpace, they are unfrozen and restored to normal. This also makes for interesting inter-galactic combat, as you have to properly estimate how long it takes to recover from this and become combat ready.<P>Imagine crews that exit HyperSpace only to be blasted to smithereens before they even wake up. Creepy isn't it?