Are you sure about Comic Sans? The only information I could find from Microsoft was on their font redistribution FAQ [1] and it says

    Until recently, most fonts that include a Microsoft
    copyright or trademark notice have only been available
    as part of Microsoft products. Although some fonts 
    remain Microsoft-exclusive, a number of Microsoft fonts 
    are now available to end users, ISVs and OEMs under 
    license from Ascender Corporation. These include 
    'Verdana', 'Georgia', 'Comic Sans MS', 'Microsoft Sans 
    Serif', 'Nina', 'Tahoma', 'Wingdings', 'Webdings' and 
    'Trebuchet MS'.

Doesn't that mean that to use Comic Sans you have to negotiate with Ascender Corporation? I couldn't find anything on Ascender's website suggesting any font at all was free to use (I didn't read everything carefully though), and about the MS core web fonts specifically this page [2] makes it sounds like you need to buy a license from them to use them:

    Monotype is proud to offer the Microsoft Web Core Fonts 
    for license to software developers and hardware 
    manufacturers who want to provide a consistent web 
    browsing experience in their products.

    Please contact Monotype for more information about the 
    Microsoft Core Fonts for the Web. 

[1] http://www.microsoft.com/typography/RedistributionFAQ.mspx

[2] http://www.ascendercorp.com/catalog/microsoft/web-core-fonts...