LibraryThing has a neat thing going with "Legacy Libraries": records of famous dead people's libraries--what they owned--and their comments/reviews, gleaned from marginalia in their books, from their letters, or from remarks they made elsewhere. Here's Benjamin Franklin's library. Here's a sample "review" from Franklin, on William Cowper's Poems: "The relish for reading poetry had long since left me; but there is something so new in the manner, so easy, and yet so correct in the language, so clear in the expression, yet concise, and so just in the sentiments, that I have read the whole with great pleasure, and some of the pieces more than once." - BF to John Thornton, 8 May 1782.
Legacy Libraries are voluntarily compiled by a user group on Library Thing, I See Dead People's Books. One can join a Legacy project already underway or start a new one. "Completed" libraries (in quotes because LibraryThing acknowledges that completed is a relative term here) include those of Ezra Pound, Tupac Shakur, Marilyn Monroe, George S. Patton Jr., Susan B. Anthony., and others. Libraries-in-progress include those of Susan Sontag, James Joyce, Emily Dickinson, Harry Truman, and others. All are linked to the "I See Dead People" page.
In addition to the whole "labor of love" thing, creating a Legacy Library might be a good side project/assignment for grad students doing in-depth independent studies of certain writers--