Explaining technology, specifically technology that is foreign to the reader, is not an easy task primarily because how you can or should explain will depend very much on the situation. For example, typically one explains something in one of the following three ways:
Literally writing "it does this," but, preferably, in more eloquent prose.
Describing the thing in action. For example, instead of saying how a toaster works, the author would simply show it doing what it was designed to do. A simple example, but the point easily applies to anything else.
You can apply comparison to "telling" or "showing." By using a comparison you are essentially saying that your new-fangled thing is similar to this old thing, but different because of X, Y, and Z, perhaps implicitly or explicitly.
All three of these types have their place in science fiction (and fiction in general), and any writer can make all of them work. While the universal rule has always been "show, don't tell," trying to show too much can be just as annoying as trying to tell too much. It's a balance issue.
If you have a new technology present in a scene, but have no reason to show that thing in action (perhaps because it isn't integral to the plot), then you should avoid telling or showing it at all. But if you need the main character to know what something does before s/he uses it, then you can't avoid telling the audience what's what. The rule about telling really should be: use it sparingly. If you can show it, then do so. If you can't without bogging down the story, then don't. "Show, don't tell" really only applies in its most rigid sense when you are talking about action. You always want to avoid telling in action. You can bring in emotions and brief snippets of things, but the reason why writers say to avoid telling is because it typically bogs down action, which is not a good thing when you want your reader to be engrossed in what is going on.
The last from the list above is one that gets used from time to time, but never really discussed. Depending on the situation, using a comparison is very much a form of telling, but it can be done in a way that a) doesn't bog down the story, and b) keeps things brief and to the point. For example, instead of describing how a futuristic printing press works, you can simply make a comparison between the presses of today and note, briefly, the differences (similes and metaphors are a must). Simpler versions use old terms with a modifier (laser toaster; you know what it does and how just by the title--a ridiculous example, sure, but it gets the point across). This method isn't used often and really doesn't apply to very complicated processes or systems, particularly if your audience doesn't know those systems, but it can be very effective.
Ultimately, if you don't have to tell how something works, or even describe it, then don't. If there's no reason for it, then that's really the only response you should have. If you do have to describe something, however, then consider how it would be best to do so; the more complicated of a system/process it is, the less likely you can reduce it to an info-dump without pulling your readers out of the story. This applies to all forms of fiction.
In the end, the best way to deal with this is to come to terms with whether you have to describe it. Don't waste space doing something you don't need to do.
What about you? If you've found ways to deal with this, let me know in the comments!
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