Google recently announced that it has promoted six Gmail Labs features to become full-time, regular options within Gmail. Sadly, at the same time, five precious Labs have lost their struggle for relevance and are being, in Google parlance, "retired."Gmail Labs is one of my favorite parts of Gmail. It's chock full of small features in beta that sometimes make a big difference. Some of my favorites are InBox Preview, which shows a simple, static preview of the inbox while Gmail loads; Undo Send, which lets you recall an email if you're quick enough to press "Undo"; and Title Tweaks, which displays the number of my unread email messages at the top of the tab. I use plenty others.

Today, many of them are graduating to full feature status. The six Labs that have made the cut include Search Autocomplete; Go To Label; Forgotten Attachment Detector; YouTube Previews; Custom Label Colors; and Vacation Dates. I use all of these Labs, and am glad to learn that enough other people value them that Google has deemed the worth keeping.

Those that didn't make the cut? Muzzle; Fixed Width Font; Email Addict; Location in Signature; and Random Signature.

Google explains in a blog post, "These decisions were made based based mainly on usage, taking feature polish and your feedback into account. We've also tweaked some of the graduating features to improve them before making them default Gmail features. For example, we've combined Go To Label with Search Autocomplete, making it easier than ever for you to find what you're looking for."

Google notes that users should notice the Labs being retired will stop working over the next few days, and will eventually disappear from the Labs page entirely. Google promises that it will continue to create and introduce more Labs, and hopes that many of them will graduate, too.