Boomerang in particular offers nifty integration with Gmail proper, adding a button that allows you to delay messages for hours or days with just a few clicks. Just one problem: It costs $4.99 per month, or $50 annually.

That's why I'm excited to have discovered , a Chrome extension that provides the same basic functionality as Boomerang--but costs nothing.

Once installed, Snooze Your Email (which also works with Yahoo, its name notwithstanding) adds a Snooze button to your toolbar. While reading any message, just click that button, then choose how long you want to snooze it: five minutes, two hours, tomorrow, next Monday, or any custom time or date.

This extension works a little differently than some of the others I've mentioned. When the time comes for an email to reappear, you have two options: a desktop reminder that pops up in the corner (and optionally beeps), and simply re-marking that message as unread (though this works only in Gmail). But Snooze Your Email does not bring a snoozed message back to the top of your inbox.

From a reminder-effectiveness standpoint, the desktop pop-up is definitely the way to go. And it's particularly cool because with one click, you can snooze the message again or open it.