With the exciting new Image upload feature, it opens up a bag of goodies.
One of the sweet little goodies is the ability to create high fidelity wireframes
In this video you can see how easily you import images from your desktop.
The web application provides desktop like functionality so you can drag any image and drop into your project.
Multiple images are uploaded asynchronously (AJAX'd). Once uploaded just go back to your editor and create a page for each image you just uploaded.
Then simply link the images using hotspots.
Publish the document or share it with your group or team.