Flickr is a great service for storing online photographs. First of all, it's FREE and allows unlimited storage and you can always download the original sized images to boot. Of course, despite these fantastic features, the FREE service is limited to 300MB uploads a month and also only being able to see the most recent 500 uploads on your photostream; the old uploads are still there but are lost on the photostream and Flickr hopes you'll cough up the $24 per year to get them back on your photostream again.
If you wanted to be REALLY cheap (which I can be :)) you could track every URL of every picture you've ever uploaded and never need to become a paying customer (but that really is kind of cheap, especially since Flickr isn't all too pricey anyway). I won't go on about all the alternative photo-sharing sites available in this post, however, because there ARE alternatives, but since I am a fan of FLICKR (and have been since well before Flickr took over YAHOO Photo's), I am going to focus on a few tricks I've developed to keep my free account alive and working for me.
The basic concept is simple: you upload your pictures in batches every month (and if you take more than 300MB of decent photo's in a month this won't really work out for you and you'll need to buy into Flickr's service, which I think is what they expect to be the case) and then you copy and paste the picture URLs into a spreadsheet for easy referral later on. I've set up a GOOGLE SPREADSHEET for this and I have categories and sub-categories so it's easy to search for what I want, and then just hit the URL to load up the picture (if it's lost on my photostream).
The problem comes in when you have to manually copy and paste one hundred shortcuts; this can be REALLY time consuming, so instead I've set up a basic EXCEL MACRO to do most of the work for me. It's still a bit laborious, but to save $2 a month is worth the satisfaction for me, although truth be told I am only moments away from becoming a paying subscriber because I really don't like the monthly upload limitations for the FREE account.
Anyway, I digress: the point is, you can keep your FREE account alive and kicking using the following tricks that I've hacked together.