Here’s a list of sites that offer hosting/storage/backup/sharing files service.
All of them offers a free account and some of them offer premium account too.
Take a look.

Divshare

file type : images, audio, programs, documents
limit file width : unlimited
time of storage : unlimited
cost of service : free

Box.net

base account:
file type: images, audio, programs, documents
limit file width : 10 MB
storage limit : 1gb
time of storage : n/a
sharing files : no
cost service : free

account premium:
file type: images, audio, programs, documents
limit file width : 1gb
storage limit : 5gb
time of storage : n/a
sharing files : yes
cost service : 4.99$/month, 49.99$/year

account pro:
file type: images, audio, programs, documents
limit file width : 10 MB
storage limit : 1gb
storage time : n/a
sharing files : no
subaccounts : 3
cost service : free

account pro:
file type: images, audio, programs, documents
limit file width : 1gb
storage limit : 15gb
storage time : n/a
sharing file : yes
subaccounts : 20
service cost : 9.99$/month, 99.99$/year

GigaSize

account free center:
file type: images, audio, programs, documents
limit file width : 300mb
storagelimit : n/a
storage time : 45 days
backup service: yes
service cost : free

account base:
file type: images, audio, programs, documents
limiti file width : 1,5gb
storage limit : n/a
storage time : 90 days
backup service: yes
service cost : free

account premium:
file type: images, audio, programs, documents
limit file width : 2,5gb
storage limit : n/a
storage time : unlimited
backup service: yes
cost service : 7.99$/1 month, 31.99$/6 months, 47.99$/1 year

Mozy.com

account free:
file type: images, audio, programs, documents
limit file width : n/a
storage limit : 2gb
storage time : n/a
backup service: yes
cost service : free

account premium:
file type: images, audio, programs, documents
limit file width : n/a
storage limit : unlimited
storage time : unlimited
sharing files : yes
download of shared files : yes
service cost : 9.99$/1 month, 39.95$/6 months, 71.88$/1 year

Badongo

account base:
file type: images, audio, programs, documents
limit file width : 1gb
storage limit : 1gb
storage time : 30 days
backup service: yes
service cost : free

account premium:
file type: images, audio, programs, documents
limit file width : 1gb
storage limit : 1gb
storage time : n/a
backup service: yes
cost service : free