May be it's time to look at this tiny tool. During the last years it has evolved from a simple hex-dec converter to a quite powerful gadget. And depart from cooking and dishwashing you can use it for your everyday twiddling.
Here are some screen shots:
You can select a file which describes bits of a 32 bit value. The list view at the right side shows the status of the bits or bit masks.
Load a identifier-value list (here "VK_xx.lst") and simply select one of the defined values in the drop down list below. The value controls will be updated immediately - naturally
Convinced? You can download a setup executable or the standalone executable from http://cid-0eb8b2026ec93d96.skydrive.live.com/browse.aspx/.Public/BitTwiddler
Oh, something I forgot to mention (one of my colleagues uses BitTwiddler since 2003 and didn't know :-) : In the bottom edit control you can enter c-like syntax, with variables 'a'-'z' where 'x' is the currently displayed value. The c-parser supports for/while/if/else statement, all c (?) operators (except pre-increment/-decrement etc.).
And if you want to monitor a value displayed in another applications control window just click the "Monitor" button and move the top of the arrow to the control.
Try it and have fun :-)