Apple ID. Problem with iCloud I took a video on my iPhone 3GS, and I don't want anyone seeing it because it's personal to me. Now I'm worried because of iCloud. I sold my friend my 2-3rd gen iPod about a year ago, and in worried he might be able to see this video through iCloud.

When I sold it to him, I gave him my Apple ID to share. I have changed it several times but I'm worried he might still be able see this video even though I gave changed pass.
If you have changed your password since you gave your friend your Apple ID, then he/she will be unable to access iCloud, or any other service that uses your ID. (Unless they are a great hacker, but that is unlikely)

Unless you give them the new password, they will have lost access to your apple account completely.

From this, I am fairly sure your video is safe.