Do you need them online for any particular reason? At 50GB, I'm assuming it's all your raw camera data, so obviously not all of it needs to be shared with friends?
If so, buy yourself a small NAS with two 500GB or 1TB drives in it (it'll cost you less than $200), and configure them as RAID-0. This will give you redundancy (not backup), and availability on your network. Get another 500GB or 1TB portable drive, and backup your NAS to that once a week, or once a month, depending on how often you add photos. Ideally store this drive offsite, or in a safe or similar, because this is your backup drive. Most NAS drives will also allow you to share the content, but due to security concerns I would probably not recommend that. If you need access to them away from home, setup a machine with SSH access to your home network, and access the drive that way via VPN (although this is a completely different topic).
Generally, with technology being cheap, I'm anti storing any valuable personal data in the cloud. If you do need or want to share some of the photos, find a service that allows that (there are plenty), but definitely don't use it as your primary storage or backup service.
Note that the above is pretty much my setup, and it's been serving me well for a few years now (with a similar amount/size of photos).