I discovered Skitch several months ago, and it pretty neat, but I wasn’t finding that I used it very much. Then I set it to be the default program that opens .jpg, .png, etc. and all of a sudden I realized how useful it was. It’s a lightweight program and you might as well use it to open image files, unless of course you are doing heavy duty image edits).
Quick and easy image creation or editing. I use the highlight function, the arrow function, and the text function most often.
Simple file-type conversion. If you look at the bottom of the window, there is a tab that shows the current filetype (i.e. jpg). If you wanted to convert that into a .pdf or .bmp, you simply click on the tab and choose which filetype you’d like to change it to. Then, click and drag the tab to wherever you want to insert that image. I use it to edit my web page all the time.
Syncing with Evernote. Assuming you have Evernote (and if you don’t, you’re crazy), all of your Skitch files will automatically be placed into a Skitch folder. Maybe not ground-breakingly useful, but handy.
-no eraser function. This just stinks. The only workout I know of is to use the white marker tool to cover up the thing you want to erase. This is not a very smooth solution! (Don’t worry, I requested the feature on Skitch’s forums!)
-no support for dragging in multiple items into a single Skitch project. The best workaround I’ve found is to use Keynote to consolidate all of the times (i.e. 3 smaller images), then take a screenshot of the grouping, and open that screenshot with Skitch.