One of the goals in creating the user interface (UI) for the upcoming G1 phone was making sure the response time was fast, so users don’t experience loading times, and it moves and acts all the time – to make it feel fluid, metaphorically speaking.

That’s according to an executive with The Astonishing Tribe (TAT), which helped create the UI for the first-to-market Android phone. T-Mobile USA will launch the G1 phone next month. TAT is a Swedish-born firm whose clients include Sony Ericsson, Samsung and Motorola.

TAT served as a design consultant for the G1. Discussions revolved around the feel of the device, the target group, language, size and more – “everything that has to be in discussion as part of the UI,” said Hampus Jakobsson, vice president of business development. Not all of TAT’s suggestions got into the device, but about 80% of them did. He said he could not reveal when TAT, a member of the Open Handset Alliance, started working on the platform.

Another concern was pure aesthetics, which was kind of tricky when the desire was to have no single brand stand out on its own, he said. While Jakobsson acknowledged the result might look a little bland, the goal was to come up with a design that was satisfactory for both the Google and T-Mobile brands.

Part of TAT’s mission is to help handset makers find ways to get the proper responsiveness and feeling in a UI without adding a lot of extra costs related to processing and power.