Okay folks, presuming this thing can go ahead, here's some information and links condensed into one post:

Map:
multimap

To: Ireland from: USA, Europe, rest of the world.
Fly to Dublin or Belfast via London - Belfast City airport 30 miles (48Km) Belfast International 50 miles (80Km) from Portaferry.   
Both airports have regularly bus services into Belfast city centre.

To: Portaferry from: Belfast
Follow the A20 through Newtownards, Grayabbey, Kircubbin then Portaferry.   

To: Portaferry from: Dublin
Follow signs for The North/Newry, then through Downpatrick to Strangford - a 5 minute ferry crossing then takes you to Portaferry.

Ferry Crossings from Strangford - a half-hourly service runs every day, except Christmas Day - only very extreme weather conditions affect crossings.
Times are as follows: - for departures from Portaferry ADD 15 minutes.
First Sailing - Mon-Fri 07:30 Sat 08:00 Sun 09:30
Last Sailing - Mon-Fri 22:30 Sat 23:00 Sun 22:30

Airlines:
Buzz
British Airways
Easyjet
aer arann
British European
Ryanair
BMI (Bristish Midlands)
BMI Baby
Go
Aer Lingus
Sceptre Tours - as Claymore mentioned

Ferries:
Irish Ferries
Stena
Ferrybooker - an online ferry booking company

Buses:
Translink, the main (or rather, the only) transport company in N.I. runs Ulsterbus, the N.I. bus company.
Ulsterbus timetables
Belfast has 2 main bus stations: Europa (Glengall Street) and Laganside (Donegall Quay). To the best of my knowledge, Laganside is still the one that serves Portaferry.

There aren't any trains. N.I. has about 2 train tracks. Neither go anywhere near the Ards Peninsula.

The area:
Strangford Lough
Starngford Lough (more of a tourism twist)
Some Portaferry info

Accommodation:
Barholm hostel
The Narrows (upmarket guest house)
Fiddlers Green - my local drinking spot, and they do B&B
GoIreland's page