My two cents. :)
Now, where in the world did this turn of expression come from? It seems as though it crops up a lot on mailing lists and comment boxes, alongside non-argumentative opinions and viewpoints regarding specific subject matter.
Oddly enough, indicating a message with the "my two cents" expression automatically gets me thinking about the humility of its author. It's as though they feel as if they're butting into a closed subject in order to score their rare opinions. You don't see the really outspoken people placing phrases like "my two cents" in the bodies of their messages, after all.
The full expression appears to be "to put in two cents' worth", as opposed to the common "my two cents" that we see on blogs, discussion forums and other Internet sites. Its origin is somewhat dubious, but can most likely be traced to the point in time when the United States issued two-cent stamps -- sometime in the late 19th century, I've read. Two cents was an amount that was considered to be of little value, so a letter with a two-cent stamp could have been seen as an expression of its writer's humble contributions.
I find an interesting parallel here. There is a biblical story that actually also involves two coins as a symbol of a humble offering (Luke 21: 1-4). "The Widow's Coins", as this story is known in some quarters, is a fairly well-known Christian teaching regarding the relationship between wealth and humility. A contribution of one's "two cents" may mirror this, in that a single tiny opinion may hold more insight than that of the many voices that have already spoken.
That's not to say that a "two-cent" contribution is usually written with this in mind. I figure that anyone who usually attaches a "my two cents" note to his or her comments only wants to slip something in -- some innocuous little piece of insight that is designed to get people thinking or looking at some alternative means of thought.
"My two cents" contributors, I figure, belong to a contextual classification. They're invariably the lurkers in a mailing list, or the not-so-active members of a bulletin board, or the relative strangers to an Internet weblog. Close friends, for example, have little or no motivation to raise their "two cents' worth" to each other because they know that their advice will always be taken seriously. The opposite would be true for the unfamiliar, though; They, after all, don't have the same guarantee that their opinions will take root.
On the other hand, it's entirely possible that humility plays a much larger role. Anyone who's hotly contesting or vigorously defending an opinion will almost certainly not have "my two cents" tacked onto their responses; They're taking a solid stance, after all. The people who stay on the sidelines watching the proceedings, however, will almost certainly post their "two cents' worth" -- because it's not their argument, and they just want to point out certain things. They don't want to butt in on the main participants.
Personally, I usually don't give a "my two cents" notice in my writings, but I think that that's because I write a lot. I have a penchant for calling a spade a spade (albeit in a very subtle manner sometimes), and I like to think that any response I write will be read with a mind that is open enough to consider it. Some people have remarked that I phrase my statements in a very personal manner, and I've told them that that's deliberate. I try to make sure that people realize that everything I tell them is my opinion and my opinion alone. They're welcome to take it or leave it as they wish.
I believe that it's unrealistic to expect that everyone out there is an open-minded person, though. In that sense, leaving a notice as to one's "two cents' worth" would merely be a subtle method of getting one's message across. That little phrase, I think, would be tantamount to saying "this is just a small opinion that you may or may not choose to consider". The wise would take even the smallest messages into account, yes. But the key, however, involves appealing for the close-minded to stop and listen for a while.
For that matter, we should always be welcome to throw in whatever comments we please (just as long as we maintain certain modicums of respect). We may think that they're worth only two cents, but in truth, they might just mean a whole lot more than that.
Just my two cents' worth, everyone. :)