Hootsuite

Hootsuite is one of my favorite applications to manage multiple accounts.  It  has been free up until recently and for most accounts it still is free except for the largest.  You can add many social networks: Facebook, including fan pages, Twitter, Linkedin,  Ping.fm, Wordpress.com, Foursquare, and Myspace.  You can add and manage multiple Twitter accounts.  This is one of the biggest advantages of Hootsuite.

I value the ability to schedule updates and drafts can be saved for scheduling again, possibly depending upon activity on Twitter in different time zones for example or to update across different accounts.. I think this is one of the advantages of Hootsuite.

Hootsuite has a great dashboard which can be customized according to your needs.  This can be keyword searches, specific users, groups, or lists.  Analytics is another advantage of the Hootsuite dashboard.

The desktop is advantageous because it is web-based.  The competitors are slow to get away from Adobe Air installations for their respective desktop applications which can be susceptible to crashes.

Hootsuite also has mobile applications for the Iphone/ Ipod Touch and also for the Droid.  I am patiently awaiting the Hootsuite application for the Blackberry.  Two thumbs up for Hootsuite.

Foursquare

Foursquare is a location-based application for social networking.  It works best from a mobile device.
Foursquare has been growing exponentially but  it took quit a while to reach one million users, grew more rapidly to reach two million.  The last growth spurt was the three million users milestone which occurred in one month.

With the introduction of Facebook Places, Foursquare really caught fire.  What can users do with Foursquare?  I don't think it has reached its potential.  I believe Foursquare, like most social media, has a great upside.  Businesses can promote with an incentive for check-ins.  You check-in to a location and the frequency can result in you being coronated as the "mayor" if you have been the top visitor that has logged check-ins.

Gowalla is the primary competitor for Foursquare.  I think the large and growing group of users will have to see what develops.