I stumbled across this great tool for creating User Interface Mockups. It is not an all purpose sketching tool like Illustrator or Google’s Layout. Rather, it does one thing really well – doing mockups of software and websites.

The unique thing about Balsamiq is that the building blocks for a mockup have the appearance of being hand-sketched – and this is intentional.

From their website:

Balsamiq Mockups intentionally uses hand-drawn UI elements, so that people don't get attached to “that pretty color gradient” or think that your mockup has actual code behind it and is “practically done”.
…wireframes created with Mockups are intentionally rough and low-fidelity. The idea is to encourage as much feedback as possible...no-one will think you'll be offended by their input, they'll know immediately that you just 'threw it together' quickly.

Brilliant!!

My first use of it was in designing the UI for a new feature I plan to add to my ETF Screener site. Here is a screenshot of what I have. It took just a few minutes:

The price tag on it is $79, which is a bit pricey sketching software, but with the collaboration features and the time savings (especially if you do mockups a lot) the price tag could be well worth it