The best bargain in water containers are recycled drink bottles - light and durable over the short term. Gatorade bottles are my favorite because of the somewhat wider mouth. Tube systems are just too fiddly and leak prone.
Good point; and one option that is often overlooked. I can't remember when someone first shared the idea with me but I felt a little silly when they did.
You mentioned Gatorade bottles for the wider mouth... that's the same reason that I've used the 1L Evian bottles. I hope to try the Evernew bottles soon because I prefer the collapsible bottles. They take up less space when empty and (for me) make a decent pillow.
