It’s been nearly three weeks since we first launched What the Hashtag?!, our community-powered encyclopedia for Twitter hashtags. In that time we’ve nearly doubled the number of hashtags we’re tracking and we’re getting some great participation from the Twitter community.

Aside from the 78 registered wiki authors, a number of people are also talking about the service throughout the blogosphere:

• Mark Rohde (@mrohde) recommended WTH?! as “a great tool if you want to engage in conversation on Twitter.”
• @hackr wrote about WTH?! just days after reporting on What the Trend, a service similar to ours, but with goals of defining all trends on Twitter, not just hashtags.
• Fred Delve bookmarked WTH?! in the educators group on Diigo.
• WTH?! made it onto Rare4You’s list of Twitter tools.
• WTH?! has been bookmarked 74 times on Delicious and 18 notes have been written about it.
• Andrew Lih (@fuzheado) says WTH?! is “about as perfect a parallel to Ward Cunningham’s original purpose of the wiki you will find.”
• HashtagDirectory.org closes shop a few days after opening as a result of finding WTH?: “…after a quick tour through its features, we are happy to say – go forth and define!”
• Antonia Zerbisias (@AntoniaZ) was introduced to “an entire feminist network on Twitter” thanks to learning about #fem2 on WTH?!

Thanks to everyone who has participated on the site or used it to look up hashtags. Also, watch for an announcement from us soon about a WTH?!-related contest (with prizes!).