It would be really nice to be able to change the unit to mBTC on BitcoinSpinner. I cant see that option currently.
Small payments are troublesome in BTC. Sometimes I put too many decimal places
I am right now working full time on the next generation of BitcoinSpinner, lit will be a full rewrite. Allowing the user to specify mBTC instead of BTC will be included along with an awesome set of new features.