Trendrr
Real-time social & digital media tracking.

Features:
Trendrr uses comparison graphing to show relationships and discover trends in real time.

Pros:
Searches and charts may be run on any key words, account, or topics. Categorized areas of search on more than Social Network sites and platforms. Site is built out with a user community of it’s own. Firefox add-ons, sharing capabilities. Consulting and account management offerings.

Cons:
Interface is a little confusing.

Pricing:
10 Free Searches, Gold $49/mo, Premium $250/mo, Elite $999/mo

Overtone
Overtone, Inc. delivers real-time customer intelligence to many of the world’s most innovative global enterprises.

Features:
Special algorithim for search, email scouring capabilities for cust svc.

Pros:
Superior search algorithm, one-on-one customer service, setup, and maintenance.

Cons:
Expensive.

Pricing:
Variable, depending on need

Radian 6
With the Radian6 listening platform, you can monitor the social web. Find your brand on millions of blog posts, viral videos, reviews in forums, sharing of photos, twitter updates.

Features:
Scan millions of sites including blogs and comments, photos, videos, mainstream news, forums, and micromedia like Twitter and Friendfeed

Pros:
Nice-looking customizable interface with reporting from entire social-sphere, that also includes web analytics. Partnered with Salesforce and build a strong CRM that is easily accessible to both agency and client.

Cons:
Results are based off key words, does not offer much insight into text analysis or human language processing (sentiment).

Pricing:
$600 – $$$$/month depending on need