Many people know that Starbucks offers discounts to people who bring their own, reusable container in for coffee.
I had always wondered how much this discount was. I read somewhere that it was $0.10, but I've also heard of steeper discounts. Then there's debate over whether it's more if you have an actual Starbucks mug, etc. I don't think it's generally promoted, and may perhaps vary by location and barista.
I asked about refills at the location nearest me and was told I could get them for $0.50. So here I am, sipping what equates to a Grande, for fifty cents, when I'm accustomed to paying $1.40 for a Tall. It's a good deal.
update (2 June 05) Not sure what deal I was getting before but the head barista informed me that using your own mug is indeed worth only $0.10 off the cup of coffee. In my previous visits I was apparently misunderstood and they thought I had just finished a cup and wanted more. What fine days those were.