Alas, there's a better way as TMO's Melissa Holt points out in a pervious tip. Using Paste and Match style will take the copied text and paste it in using the current document's formatting. This is what many of you may expect will happen when you paste in some text, so it's nice to have it as an option. Unfortunately for those of you who like keyboard shortcuts, the relatively simple Command-V turns into Command-Option-Shift-V.
Thankfully for you all, there's a fairly simple tweak which can be made to OS X that saves you from mashing several keys every time you want to paste some text. Instead of doing the finger gymnastics that is the default keyboard shortcut to “Paste and Match Style,” the shortcut can be easily set to good old Command-V.
To do this, go to System Preferences, Keyboard, select the Keyboard Shortcuts tab, and select “Application Shortcuts” from the left-hand menu. To add the shortcut, click the plus button at the bottom and enter (very precisely and sans-quotes) “Paste and Match Style” for the Menu Title, move down to Keyboard Shortcut, and hold Command and V at the same time. Press the Add button, and you're done!
Keyboard Shortcuts
For those of you who still want the standard Paste feature to be accessible via keyboard shortcut, simply follow the instructions for Paste and Match Style, substituting “Paste” for the Menu Title and whatever you want for the Keyboard Shortcut. I personally switched it to Command-Option-Shift-V because it only seems fair.
After all that, give it a spin! Copy something from a website, paste it into a TextEdit document, and notice the lack of styling from that web page. Pretty cool, eh? Even cooler is that you can easily reassign other keyboard shortcuts in the exact same way.
The only thing to be aware of once you've made this tweak is that there's a slight chance one of the apps you use might get confused with this particular set-up. The only app I've ever had trouble with was TextExpander but I believe it's been fixed. So if you run into some weirdness, try removing those shortcuts from the Keyboard Shortcuts menu.
Enjoy!