If you get a Google+ account, one added benefit is that you can now upload an unlimited number of higher quality photos (up to 2048 x 2048 pixels) to Google+ and/or Picasa Web Albums, for free. There are some differences in how your photos are handled and stored, depending on if you upload photos in Google+ or in Picasa Web Albums. The details are explained here.
free storage space
Dropbox Free: Get Over 2 GB Free Extra Storage Space
Participate in Dropquest 2011 and get up to 1 GB of free extra storage space for your Dropbox account. Complete other tasks within your Dropbox account on Dropbox’s website to get even more free extra space, adding over 1 GB more to your Dropbox account, for a total of over 2 GB of free bonus Dropbox storage space.