Here's another one: I've seen the word "secular" used a bit lately, and in the words of Senor Montoya, "I do no' think it means whadda you think it means."
"Secular" means "not religious" (more accurately, I believe it's the opposite of "sacred"). The point is, you cannot have "secular religions" -- that would be a contradiciton in terms. I assume that when people propose the existence of such things they mean "secular institutions that resemble a religion in some respects", which, I'll admit, doesn't roll off the tongue so nicely, but nevertheless actually makes some fucking sense.
It's not a phrase without it's problems, though. The whole tactic of trying to claim that outwardly secular institutions or beliefs are in fact "religious" almost always backfires on the people making such claims. In order to make these claims fit, they usually have to water down the concept of religion to the point that it amounts to little more than "a bunch of beliefs that you can't actually prove". Applying this definition back to their own religion doesn't generally make it look that flash.
Similarly, the notion of worship often gets singled out for this treatment, since it's a fairly central component to religion, and often the one that least applies to the supposed "secular religions". The claim is often that we all worship something -- capitalists "worship" money, scientists "worship" Darwin and so on. But we don't -- we don't pray to money, we don't believe Darwin can be appealed to to perform miracles, we don't claim that either of them are superior to us -- if our relation to such things is one of worship, then "worship" has to be watered down to no more than "think is pretty good", and I'd be willing to wager that your average Christian would object to their relation to God being described as merely "we quite like Him."
Of course, sometimes that's not a problem -- there are two possible cases where someone might claim that a secular institution is religious. The first is a religious person making the claim, usually in response to a slight against their own religion: "You may think my religion is silly, but you're just as religious about X" -- in this case, the watering down effect results in something of a backfire. The second case, however, is where a non-religious person criticises someone's viewpoint, meaning to belittle it by likening it to unquestioning dogma or foolish superstition. In this case, since the person has little or no respect for religion in the first place, there's no danger of a backfire. Nevertheless, by watering down the concept of religion, they're also watering down the rhetorical technique that they're trying to get mileage out of.
OK, that got quite preachy and formal -- you'd think I had a crucial point that I was leading up to. Um... use "secular" right and don't call something a religion unless you mean it? Toodles.