Frengo is a newish nanoblog service that makes it easy to both subscribe to topic areas and to create your own feeds. Compared to somewhat similar services (Twitter, Jaiku, and Pownce), it has a few twists. For one, it's built for the 16-to-30 demographic and is thus a big SMS play. The Frengo founders also have good connections with the mobile carriers, and have managed to get carriers (notably Sprint subbrand Boost) onboard with the service.
As the carriers are raising their a la carte per-message rates on SMS in order to push people into all-you-can-eat bucket plans for text messaging, you know they've got to love Frengo's SMS-centric model. If you're not careful on Frengo, you can quickly find yourself deluged with horoscopes, sports news, and quizzes about celebrities. It's easy enough to turn off the mobile notifications and get updates on the Web only, but for a few minutes after you sign up for these services, your phone is going to be buzzing like mad. A WAP-based version is in the works.
Frengo's other trick: It bribes its users by awarding points for activities, like signing up friends. These points can be redeemed for prizes, such as ringtones and prepaid phone cards, all the way up to iPods and Xboxes.
I am of two minds on Frengo. I like the Web service. In addition to creating text updates, it has other post types. You create polls and quizzes, which can be fun. (See also Pownce, which lets you create file-transfer posts, link posts, and invitations.) Frengo also has a directory model that other nanoblog tools lack. When you want to sign up for content, Frengo makes it easy to find it.
The service also let you put your friends in groups (as does Pownce) and select who gets the updates that you write.
On the other hand, I really don't like the way the points system, the friend invitation system (it asks for friends' mobile numbers), and the SMS focus of Frengo all collude to drive up SMS adoption and to get people to use--and pay for--more messaging services. While it's likely that a service like this, built hand-in-glove with the carriers, will grow its user base much more quickly than a crunchy-granola startup such as Twitter or Pownce, I feel it's manipulative, and that alone will keep me off the service. (And as a current Twitter and Pownce user, I am not about to start managing yet another circle of nanoblog friends.)
Still, Frengo looks like a decent business, which is more than you can say for most of the current nanoblog services. I would not be surprised to see it win a large number of users.