It's be cool if the 'annually' version could also take into account reserved pricing, since doing the 1-year reserved thing would be the sensible option if you wanted to use a machine as an always-on VPS-style box. E.g. the m1.small instance is $797.16 annually (what the page currently reports), but with 1-year "heavy utilization" reservation it ends up being a more reasonable $291.64 (including both the cost of reservation and the instance cost).
The calculator provided by Amazon does have the option of factoring in the Reserve Pricing and will give you the monthly and annual charges as separate line items.
We posted a calculator that does exactly this: https://scalyr.com/cloud. It will let you compute a "normalized" monthly cost for the various reserved and non-reserved options, customized for your usage and cost of capital, so that you can make an apples-to-apples comparison. You can also compare with other providers.
