Of the 100 most mentioned brands on Twitter, the vast majority do not have corporate accounts. Imagine the influence that these brands could have if they were engaging in conversations with consumers via Twitter. They could answer questions, respond to reviews and, in general, gain insight into how their customers feel about their brands.

So I’m calling out some of the top 100 brands that SHOULD be on Twitter that aren’t… yet.

#4 Apple
I’ve seen the commercials. The Mac is supposed to be the cool guy. Since IBM is on Twitter @ibmevents, I’m going to have to say that Apple is a step behind on this one. I know I’d appreciate a little Twitter love when my iPod shows that sad iPod face…

#7 Microsoft
Those Zunes aren’t going to sell themselves.

#10 Coca-Cola
Coca-Cola spends millions on web site promotions like the CGI Happiness Factory, but they aren’t willing to sign up for a free Twitter account and assign a PR or marketing staff person with the task of monitoring the tweets related to their brand. I can’t imagine how many people are already talking about how they’re craving a Diet Coke right about now. Or maybe that’s just me!

#18 IKEA
There’s an entire (un-official) blog dedicated to do-it-yourself-ers that modify Ikea products for added efficiency. They could be talking about new product releases, decorating ideas or even helping people figure out how to turn a box full of parts into a new bookshelf!

#25 Skittles
The new Skittles web site is devoted to Web 2.0 with links to YouTube, Facebook and even Twitter. But the company doesn’t even have its own Twitter account? Lame. Well, lame and a completely incomplete launch.

#29 Lego
Anyone on Twitter that follows @GuyKawasaki (who doesn’t follow Guy?) will see all the crazy Lego creation links he posts. Wouldn’t it be phenomenal if Lego was also posting links to these creations?

#47 Subway
Wouldn’t you like to know what Jared is eating for lunch today? I sure would.

#75 Budweiser
Maybe because I’m from St. Louis and I’m still a little salty about the InBev takeover… but seriously! They could be posting about new commercials, where the clydesdales will be making appearances… I’m going to stop there. I guess I’ll have to settle for the alcohol-induced Texts from last night blog for now.