Travelling Utilities:

Maps and itineraries:

• Google Maps
• ViaMichelin
• MapQuest

 Some authorities:

• Lonely Planet on line
• National Geographic  
• ViaggiareSicuri (Travelling advices from Ministero degli Esteri & ACI)
• iTravelNet
  

More Utilities:

• global:
• Oanda Currency Converter  
• Meteo (at KataWeb)
• Tourist Offices Worldwide Directory

• local:
• hostels
  
• parking in Manhattan: Icon
• JFK, EWR, LGA airports
• NYC at answers.com
  
• velib Paris, RATP
• TPG
  

Some Travel Agencies:

• eDreams and eViaggi
• Travelocity
  
• Expedia.com  ( fr , uk , it )
• Orbitz 
• Hotwire 
  
• ( Etn )
• some low cost (mainly Europe):  AppleFares,  SkyScanner, Openjet, Gooflight ... 
  
• hostel accomodations
  

Travel Companies:

•  Trenitalia, SNCF
  
•  Alitalia, AirFrance
  
• Low-cost Airlines: ( this list (at Etn) and this one (at iTravelNet)) 

  UK based	Germany/Switzerland based	Spain based	Italy based	France/Belgium/NL based
  Ryanair EasyJet bmibaby Jet2 FlyBe	EuroWings Air Berlin TUIfly Helvetic	Vueling AirEuropa	Blu Express (within Italy, +Mediterranean holidays) MyAir: deprecated!, see note here Meridiana	Brussels Airlines Transavia
  Other: Virgin Atlantic (based at London, to US, Far East, southeast asia, Caribe, Africa) AirAsia (based in southeast asia + Australia, London, Paris)  Wizz (to eastern Europe) BlueAir (Romania)

            USA

• JetBlue (mainly JFK -> Florida, West Coast etc)
  
• SouthWest (almost everywhere in US)
• Frontier (based in Denver)
  
• Spirit (some service East Coast -> southeast and LAX)