Excitement ran high for tablets today in wake of the iPad 2 announcement. Meanwhile, interest in smartphones is as high as ever. The post-PC era is upon us. We've made the case that these mobile devices are just part of a larger whole: the mobile cloud. Companies like Google and HP want to sell cloud services to mobile users.

But there's a big problem with that vision, and that's the mobile bandwidth bottleneck.

As smartphone and tablet adoption spreads, more bandwidth-hogging services are springing up. On the consumer side, there are services like Hulu, MLB.tv and Netflix. But it's not just consumer apps that will suck up bandwidth. Cisco is pushing mobile video for businesses with products like mobile versions of WebEx and its new unified communications app Jabber. Its forthcoming Cius tablet is all about mobile video conferencing. Apple's FaceTime will surely be a contributor to video conferencing bandwidth as well.

But how will carrier networks handle all this data?

Red Monk's Stephen O'Grady graphed how his bandwidth use skyrocketed after he started using Netflix Watch Instantly in January:

O'Grady was grandfathered into AT&T's unlimited data plan, but that plan isn't an option for new customers. Now AT&T's largest data plan is four gigabytes for $45 per month - it costs $10 per gig over that. O'Grady graphed what his mobile usage would cost him on various carriers if he hadn't been grandfathered into the unlimited plan:

The cost of mobile data for devices other than smartphones is even worse.

Until this problem is solved, the mobile cloud will be significantly hampered. O'Grady highlights the business opportunity for developers to build apps to monitor and manage bandwidth consumption. But that's just a bandage. Carriers need to solve this problem, and solve it quick.

In response to AT&T's bandwidth caps, Fake Steve Jobs compared the iPhone to Meet The Beatles:

Now there was a lot of demand for that record -- so much that the plant that printed the records could not keep up. Now here's the lesson. Do you think the guys who were running Capitol Records said, Gee whiz, the kids are buying up this record at such a crazy pace that our printing plant can't keep up -- we'd better find a way to slow things down. Maybe we can create an incentive that would discourage people from buying the record. Do you think they said that? No, they did not. What they did was, they went out and found another printing plant. And another one and another one, until they could make as many records as people wanted.

Sadly, instead of taking Fake Steve Jobs's advice, other carriers have followed suit.

I'm not one to ask "Where's my flying car?" I'm just happy to have clean water and to live in a world that hasn't been decimated by nuclear war. But assuming we take care of bigger problems, like global warming, I can't help but wonder if future generations will be asking "Where's my mobile cloud?"