Android App: Perfect Task Switcher
There are surprisingly quite a few apps available in the android market that provide a visually attractive app switching experience, however not all of them do it that well. One of the better ones out there is called Perfect Task Switcher (at least they sound confident right!). Perfect Task Switcher is an ad-supported free app, but they provide you with the option of disabling these ads which gets them big bonus points from me.
The app provides you with a swipable preview of running tasks when long pressing either the search key or tapping your home key. Both keys are fully customisable too. The previews are of a high quality (higher than most of the alternative apps) and the devs will add in even higher quality previews for rooted users in a future update. I'd definitely recommend giving it a go, it's free and as it's in beta it can only get better!
Below information is from the developers webpage:
FEATURES * Quick and easy task switcher * Elegant design in Froyo and Gingerbread style * Integrates very well with all common home screen replacements like LauncherPro, ADW and Zeam * Preview of running tasks * Quickly stop (kill) foreground tasks to free up phone memory and save battery lifetime * no root required on your phone HOW IT WORKS * Launch Perfect Task Switcher by pressing your HOME key * Press your HOME key a second time to switch to your default launcher (with support for LauncherPro, ADW, and others) * Swipe through the previews to quickly switch to a running task KNOWN ISSUES * Preview graphics are of poor quality. This is a limitation by the Android OS itself. Improved previews for rooted phones and tablets is underway... * Gingerbread and some CyanogenMod versions do not show previews. This will be fixed for rooted phones soon. * Perfect Task Switcher does not support Honeycomb. * Not all key shortcuts (like long-press home) can be supported by this app. This is a limitation of Android and cannot be circumvented. REMARKS Task preview graphics are not supported on all Android devices. Quality of the preview graphics is very limited and depends on the manufacturer. As this is a BETA release we've enabled Google Analytics to track your devices capabilities. This anonymous reporting can be disabled anytime through the application's preferences screen. We're working on improving device compatibility and adding high-res previews for rooted devices in one of the next releases. Stay tuned!