The lack of Cut and Paste in Windows Phone 7 has been tossed around quite a bit, and Microsoft's response was that they wanted to try and create shortcuts that minimize the need for such a workaround. Features such as being able to tap on a phone number or address in a web page or email are obvious ways that they've accomplished their goal, but we've come accross another shortcut that may help you out.
Often times, you can select a word or phrase in an app. For example in Internet Explorer or Word, you can select a word or words. It turns out that there is a quick and easy way to do a search in the Bing app on the selected text. Simply tap the hardware search button and the Bing app opens, with your text already being searched. Sweet yes?
Bonus Tip: This one is courtesy of Paul Thurrott. You can quickly and easily dismiss toast notifications (Text Messages, WeatherBug Alerts, etc.) by swiping accross them from left to right.