Here are some useful links if You're planing a trip to Åland.

Eckerö Linjen	www.eckeolinjen.se	Trafficates: Grisslehamn - Eckerö
Viking Line	www.vikingline.se	Trafficates: Stockholm - Mariehamn (Långnäs) - Åbo
Silja Line	www.silja.com	Trafficates: Stockholm - Mariehamn (Långnäs) - Åbo
Skärgårdstrafiken	www.alandstrafiken.aland.fi	Trafficates: Åland's and main-Finland's archipelago.
Åland's Turist Information	www.GoAland.net	Very useful Information about Åland.
Ålandsresor	www.alandsresor.fi	Cotages, hotels and travel packages