I love using Rubber Cement for various projects. Normally gluing paper to paper. It doesn't bubble or wet the paper like regular liquid glues.
I normally don't use it on photos in scrapbooks. Use other adhesives for that.
Rubber Cement is great for altering books, by recovering the outsides with other papers.
I have noticed that I didn't let a page that I used Rubber Cement on completely dry before putting it into the sheet protector, the fumes will "melt" the protector plastic and cause it to bubble. The protector will never be smoothe again afterwards. If the RC is completely dry, this doesn't happen.
So it makes me a bit nervous but it still works great in many projects.
I use FabriTac for almost everything - the one by Beacon - and it is the only liquid I have ever used that causes absolutely no warping or bubbling at all...and it is the cheapest by far since it is not a scrap product.