Locking up a file

[kjs862]

Is there a way to lock a file up and keep it from being opened? I was thinking it would be nice lock this file I have and only be able to open it with the correct password.

Ken

[After G]

Use an encrypted disk image.

1) Open Disk Utility. From the File menu, make a blank image.
2) Make sure you pick "Encrypted" and "Read-Write" as your options. Pick a size that's a little bigger than the file you want to protect.
3) Set your password. The image should be where you saved it to.
4) Put your file in. You're done.