As was customary in 1908, the candidates themselves did not attend the nominating conventions (the first president to attend a convention was FDR in 1932 who appeared to accept the nomination to dispel rumors about his health).
However, just as in 2008, whenever there is no candidate present, there are representatives to do his bidding. In 1908, Charles Bryan, came to represent his brother, William Jennings Bryan, who was expected to be the Democratic nominee: On July 6, 2008, The Denver Post reporter, Samuel G. Blythe, writes: "Charles Bryan's vocabulary seems to be comprised of the phrase: 'Bill says to do this,' which he repeats to the men who think they are running this convention with monotonous regularity. At that, other words could seem to be superfluous, for what Charles says Bill says to do is generally done and forthwith."
During the convention, William Jennings Bryan stayed on his farm, Fairview, near Lincoln, Nebraska. During the day he cut some alfalfa, and area farmers dropped by to visit with him. That night he sat with his family and one or two close friends to listen by telephone to the convention. (Organizers had rigged a megaphone to a telephone in the convention hall, and this was connected to a long-distance telephone line.) In this way Bryan heard the roaring of the delegates, when his nomination was made official at about 3:40 the next morning. For the third time, the Democrats turned to the popular candidate from Nebraska, and John W. Kern of Indiana was selected as his running mate.