I am looking at My Family Tree for direct ancestors that generates a 250 page list. If I want to go to page 200, it is very laborious to jump to 250, then jump back a small number of pages at a time. If users could submit a page number to jump to, simple interpolation would let us get to the neighborhood and then only have to jump through a small number of pages to get where we want to go. If the computer or browser crashes, entering the page number would let the users recover much faster than having to use the present method.
Another thought: it might also be useful to instruct the program to jump to the first person in the 35th or 12th or 40th great grands list in the Family Tree.
What ever you decide to do, it should be a great improvement over the painfully slow method used now!!!