Hot Gloo is an online wireframing tool designed with information architects in mind. The heart of the app is a palette of the main site elements IAs use in wireframes every day. The elements can be easily positioned and resized by dragged, making Hot Gloo a cinch to use. Throw in the ability to share your designs with clients via the web, and this app could the wireframer's new best friend. You can add multiple users for collaboration, too, either as editors or reviewers.