I agree with Kitty Hawk but one word of warning, the Blue Line of the T is not exactly high speed rail service. It's not unusual to wait 25 minutes for a train from airport station or from Government Center when heading back to Logan. Just keep an eye on your time. Don't get me wrong, the T is great, but I've been burned too many times on the blue line.

Other alternatives to/from Logan are the Airport Water Shuttle or a cab but with tunnell traffic the cab isn't so efficient either.

Enjoy!