Lobster gurgled happily, sounding much like they were saying:
IKWYM.
There's always the IE Tab plugin - uses IE to render pages within a tab in FF - and can, IIRC, be set to do so automagically for certain domain names. The original IE Tab seems to have stagnated, since the original dev has apparently moved to Linux, but there appears to be a fork - "Coral IE Tab" - which is live, as well as another plugin - IE View.