Not everyone has photoshop skills (one look at my website shows that I don't--allow I plan to change the site layout and design soon!) and typically when I wireframe workflows I use a pen and a blank piece of paper.  It will have little lines and squares, and scribbles and it hardly looks like a webpage.  I recently cam across this cool tool called Balsamiq.  It makes it so easy to drag and drop UI elements and construct a mockup.Here is an example of a mockup I made for an operations dashboard--this literally took me under a minute.It is written in flex and you can save your images, if you do a lot of mockups you can also buy a version for $79 (which is pretty good considering the time this can save).  It was easy to learn and very intuitive.  I wish it had even more UI elements and the elements were more flexible (like being able to add buttons in a table)--but it is still really cool.If you ever design web sites, or need to communicate requirements this is a great tool for quickly putting together wireframes.  Check it out at: Balsamiq Mockups.