I, too, have been searching in the 1906 records for a relative. Your task may be painful, but not impossible. Painful, because a lot of the passenger list image are not indexed, so can't be searched. TheShipList.com might be useful in establishing what fleet/lines were operating in 1906 - then once those are narrowed down, you could query for a listing of all the ships of that line -
http://www.theshipslist.com/ships/lines/index.htm
You might want to start with Hamburg-Amerika Line
http://www.theshipslist.com/ships/lines/hamburg.shtml
I was fortunate in that on FamilySearch, I located a Passenger List that contained the name I was looking for (but no other identifying info). However, paging through the document I found the name of the ship (White Star Line (UK) SS Teutonic) the date of arrival and that the port of embarkation was Queensland Ireland (and not on the continent). I then did a search of the passenger lists on Ancestry on the name but came up blank. What I did then, might be of value to you - I browsed the New York, Passenger Lists, 1820-1957 collection by date (right pane). I then went through each of the pages until I found the record I was looking for (the jury is still out if I have the right person)