My partner has started an archival project scanning historical family photos. She currently uses Picasa/Google drive, but is bumping up against the upper storage limits. She is looking for the best remote storage option. She's not as concerned with sharing, though eventually she may like to do so, she is mostly interested in being able to access them remotely and cross platform. (She has a macbook, an android phone, and we have PC's at home.) I use imgur myself for basic storage/sharing, but I'm not sure that's the best option for her. Anyone have any thoughts or suggestions?
I use Dropbox for my general remote-access file-drive needs, but that only gets you 2GB for free (plus a half gig for every referral). It does have a host of ways to access it, though, from a bunch of mobile apps for most of the things you'd expect, to a web interface, to an app for Windows that I use that's pretty slick (folding almost invisibly into your regular folder architecture) , to mac and Linux apps which I don't have any direct experience with but which I imagine are also great. You can use it to share stuff publicly too, if you want. How much space does she need?
She's currently using 3.5 gigs in Google Drive and has just started the project. If I was truly tech proficient I would set up some sort of home server, but that is well beyond my skill set.
mega.co.nz offers 50 GBs of free storage, all locally encrypted. It works well, I started using it to store files. Sync functionality is coming soon.
Honestly, if you're hitting the limitations of the free layer of PicasaWeb, you're going to hit the limitations of the free layers of every other high-quality reputable site, too. If you otherwise like PicasaWeb, it's $5/month to get another 100GB. Flickr offers a "Pro" level for $25/year that gives you "unlimited" storage, so would be cheaper.
You might look into getting something that will go through all the photos and save them with more efficient jpeg compression. I cut out like 2mb from 6mb photographs doing that, sometimes more.
Pay money if the project is important to you. Also, KEEP OFFLINE BACKUPS! Your partner is going to delete the image directory by accident one day and your only hope of recovering the last six months of work will be the USB hard drive you copied the images to and then put under your bed.
Interesting fun fact: It costs $50/month to get 1TB of drive space for Picasa/Google Drive. If you buy the sweet-but-expensive Chromebook Pixel, it comes with 1TB of space for three years, which works out to an $1,800 value -- but the laptop itself is "only" $1300, so basically if you want the space, they're paying you $500 to take the laptop.
I know it's the red-headed stepchild of photo sharing services, but Flickr has been good to me for the last five years I've used it. Unlimited photo uploads (50MB per photo limit) and archiving of original size images for $25 a year.
I'm also going to give a nod to Flickr. It's cheap and reliable with some handy features. It could do some things better but it's always worked for me. Its latest IOS app is terrible though, it seems to consider that uploading photos is the last thing you'd want to do with Flickr but that's about my only complaint with it.
If I recall correctly, they'll archive the original size regardless of whether or not you're on the paid tier but you won't get access to them unless you pay up. You can't see any more than the 100 most recent photos either unless you've a Pro account. I'm not sure how sites like 500px or Instagram (vomit) work, but the fact that Flickr keep your photos even if you're on the free account makes it a useful site. They're only the red-headed stepchild because they pre-date the smartphone boom - in most areas (other than their apps, which Nellie rightly points out tend to be hit-and-miss) they're actually pretty good. And the API is (or was) pretty awesome.
