Copy-Paste functionality in WP7 phones is like a boon in the phones. You copy a text or a sentence and then paste it. This saves your time and energy and you are much happier. But taking this one step ahead, you can also paste a single text multiple times. Pocketnow has also comeup with a video for this.
Worth Reading,
Update WP7 to include Copy-Paste functionality
You will see that once you paste something in your phone, the Paste icon disappears and you have to copy again, if you want to add the same text again. The below video shows you to how show the PasteIcon multiple times and copy the same info again and again.