how big is the file and how long do you want to host it for?
www.yousendit.com
offers to store a file up to a gig in size , but only for a week.
www.Filefront.com
in my opinion is the best file storage place. You have to get an account, however you can store huge files, unlimited bandwidth and you can check how many people downloaded it. Plus i get good speeds when i download a file.
www.megaupload.com
offers smaller storage maybe like 100 mbs or something, but doesnt require you to sign up and can host it for as long as someone downloads the file within a 30 day period.
http://rapidshare.de/
is a great site aswell. i think its the biggest one there is. they say thier servers have 105 Terabytes of hard-drive capacity. however max size of files is 50 mbs. , but the file wont get deleted and can be download unlimited amount of times