Using 3rd Party Twitter Applications such as TwitPic allows you to upload GIF, JPEG, PNG Images up to 10MB in size, & Videos up to 3:00 Minutes in length (In most Formats). After Uploading your Multimedia, You’re first asked if you want to add your Location to your Post. The Final process is a 114 Character Limit describing what you are Sharing. Finally, the Multimedia is shared to your Twitter Page.
Using 3rd Party Applications for Multimedia isn’t typically used, since Twitter enables you to Upload a Photo or Paste a URL into a Tweet via Twitter.
The only benefit I could really see using TwitPic, is that when you Upload your Multimedia it has a Possibility of bringing New Traffic to your Twitter.