I also love my Spibelt, but I usually only use it for races to carry my camera and keys. One nice feature is that it has a slip pocket in the back of the inside main pocket, so you can put your keys in a seperate compartment from your phone, to avoid accidentally scratching the screen! I also normally wear it under my shirt with the pouch at the small of my back. No one can see it, and it doesn't move around!
One suggestion with the hydration belt is just to give up having it around your hips and just wear it at your natural waist. It isn't as comfortable and it takes some getting used to, but it won't move - and after a few runs, you'll stop noticing it at all. This is particularly a problem for those of us women with larger hips and smaller waists, as they're made to fit men, who are pretty much straight up and down. I have a Nathan hydration belt in a women's model and it's better at staying on my hips that my husband's Amphipod, but I still give up and just wear it on my waist - I hate adjusting the belt every 30 seconds! I also don't know if you have the Amphipod with the velcro or the snap buckle closure, but I recommend the snap buckle for women, because it makes getting a precise fit much easier.