To get to Epcot I like to take the launch to MK and then monorails to Epcot. This is not a quick route (by any stretch of the imagination) but the view of Epcot as you loop through FutureWorld before entering the station is worth the time... I really piques the anticipation. If I'm in a hurry, I'll take the buses. If I'm in a real time crunch I'll take a cab (we don't tow) which you can call and catch at the outpost.
To get to Boardwalk, well, it depends. If you have lots of time and can freely access Epcot and really like launches, you can follow the directions above to get to Epcot, travel through Epcot (maybe taking a FriendShip) to the International Gateway, catch the launch there to Boardwalk (or DHS beyond). This could easily take 1-1/2 to 2 hours, but it is quite scenic: three boats, two monorails and a fair bit of walking, through two worlds and multiple countries, whew!
The faster way to Boardwalk (or pretty much any other resort) is to take the launch to MK and then find that resort's bus. If you need to do this after MK hours, take the FW bus to Downtown Disney and from there to whatever resort you want, DtD buses run quite late. Or, again, taxi or drive yourself.
[Sorry, I didn't see MikMouse had answered inside the quote. I didn't mean to repeat so much, but glad to hear I'm not the only one who uses such circuitous routes!]