See (tye)Re: why a nodelet can be kept against author wish?. Basically, if you noticed a typo, you can go back to your node and edit it. If it's been posted to the wrong section, the janitors can clean that up. If your node is just wrong, you can use the <strike>...</strike> tags to mark the information as invalid, but please also write a small update explaining your error so others can still learn from it. Other than that, just leave the node :)

Your first line says "message", but the rest of your post talks about nodes. Which did you really mean?

If the answer is "node", as the other respondents have assumed, here's my opinion.

This is an age-old conundrum. The only really good advice is, Don't post until you're absolutely sure you want the entire world, including your grandchildren, to read it. Therefore, sleep on it, and preview, preview, preview. In many systems (USENET, for example), there is absolutely no possibility of recall or correction. In others (such as wikis) there is an enormous degree of post hoc editability, giving rise to a phenomenon known as wiki mind wipe, with a consequent echo of policies and mechanisms to combat it. Fortunately, PerlMonks is a little different from most other systems.

If you post, and it really is only an ohnosecond between the time you post and the time you regret, then yes, just edit the node to replace its contents with something like "sorry, mis-posted. please reap." The quicker you can do it, the smaller the window in which someone might have read the original content. The real deal-killer is if someone has replied to your node. Once that happens, edits to nodes should be limited to "Update"s, generally. And of course there's always the risk that someone has begun the process of replying to your node with its original contents, and not finally submitted their reply until after you make your change. If this happens, there is a great likelihood that the janitors will undo your edit.

That having been said... There is a FAQ on this issue: How do I change/delete my post? I assume you read it before posting your question. Oh, you didn't?

Somewhat relevant old discussion: Re^5: Unwritten rules variably applied. (lines)

Update: ysth kindly reminded me that it is possible to try kill a message on USENET, using a "cancel" message. Even so, it is rarely done, and very few USENETters indeed even know about it, let alone how to do it.

I don't suppose there is any "recall" utility on perlmonks that intercepts nodes that need to be reconsidered, edited, or slowly strangled into oblivion, is there?

That's what the Preview button is for.
The notion is that after you wrote, previewed, edited, checked, previewed, spell-checked, took another look, and only then posted, you have no rational reason to recall the post.
If you decide to post commando, you deserve the result, but can still amend them.
For example, if you realise that "Wait! Wait!" is slightly less good a title as, say, "Is there a way to recall or erase posts that have been submitted?", there's always usually an update button handy

Except, of course, there is no Preview button for (ill-considered) messages or considerations.

But excellent point!

there's always an update button handy

Except for categorized questions and answers which become owned by QandAeditors immediately, so I can't edit them. Yes, there's still a preview button, but I'm used to the possibility to update my nodes, so I posted hastily, and was shocked I can't update.

:-)

#!/usr/bin/perl -w
use strict;
# use Quick::Fingers;
use constant _onhosecond => y; # replace "y" with your chosen value be
+fore executing
use constant _you_are_really_quick => z;     # likewise

my ($time_to_move_cursor_to_browser_stop_button, $latency, $server_rea
+ction_time);

if ( (_onhnosecond + $time_to_move_cursor_to_browser_stop_button) < (_
+ohnosecond + $latency + $server_reaction_time)  && _you_are_really_qu
+ick ) { # 1.
    print "whew! Not exactly 'recalled' but good enough.\n";
} else {
    print "sorry!\n";
}

# Time waits for no man, except, maybe, the very quick.
[download]

^{1. Syntax error in Line 9 or bio-physically unlikely.}

More seriously, your second para addresses an issue which arises when a consideration addresses only one problem in a post with multiple failings -- say, a case in which formatting is borked AND the node was approved to an inappropriate category. TTBOMK, the only current answers are (1)to beg a Janitor to unconsider and then reconsider or (2) wait for the first to run its course and reconsider for the second flaw.

And "self-reap?" -- No, for various reasons, including the potential mischief that could allow. Reaping powers are reserved to a higher Order.