One of the most compelling features of Samsung’s Galaxy S lineup of handsets is the custom Android user interface (UI) – Samsung’s TouchWiz 3.0, which is not only clean, fast, and versatile, but also boasts a number of exclusive features.

In fact, in the emerging realm of Android devices, the UI is one of the main differentiators, and most of the fervent Android-backing handset manufacturers have their own respective UI – while Samsung has TouchWiz 3.0; HTC has Sense; Motorola has MotoBLUR; and Sony Ericsson has the UX Platform.

In the Samsung Galaxy S smartphones - two of which, T-Mobile’s ‘Vibrant’ and AT&T’s ‘Captivate’, have been released; while Sprint and Verizon versions are in the offing -, the TouchWiz 3.0’s lock screen is a simple, visually-attractive, and is a cut above Android’s standard version, both aesthetically as well as functionally.

Furthermore, by expanding the homescreen space, and consolidating common functions, TouchWiz 3.0 enhances all the three aspects of Google’s stock version of Android – namely, three open homescreens; a “drawer” for storing apps; and a “shade” for running processes and notifications.

In addition, along with the standard 6-10 widgets of Android, Samsung adds eight more exclusive widgets – four for different kinds of clocks, like accuweather clock, calendar clock, dual time zone clock, yahoo finance clock; and four others including daily briefing, buddies now, days widget, and feeds and updates.

In all, the Samsung TouchWiz 3.0 UI does not simply ‘re-skin’ the Android; it actually improves the use of the homescreen space very effectively.