I erased a couple video from my nikon cam...

Yes. However you do need recovery software. As long as you did NOT format the card there is a very high chance to recover your images. If you just accidentally hit "Delete" instead of "Format" then here are a few links to software that will allow to you to recover your images and video.

http://download.cnet.com/Digital-Photo-Recovery/3000-2248_4-10257774.html?tag=mncol

However it is not free.

"The software will recover lost, deleted, and formatted digital photos,audio and video files from fixed or removable media such asCompactFlash, Memory Stick, miniSD, MultiMediaCard MMC, SD Card,SmartMedia, xD Picture Card, MicroDrive, FlashCard, PC Card, Zip disk,floppy disk, or hard disk."
- Download.com

If this sounds like your problem, this will do it.