This one is easy...
Create an alternate view of lastn that allows the entries to be sorted by logdate as opposed to eventdate.
And.. a bit more difficult...
Give users the option to have their default page shown in logdate order or eventdate order.
These features are meant for people like me who tend to write something in a paper journal that they intend on writing in their LiveJournal eventually. They post 80,000 entries before they get around to typing the hand written entry. They want the date on the handwritten entry to reflect the date it was created, so they change the event date to be equal to that time. Now, the entry no longer shows up on the front of the lastn view, as they are ordered by eventdate and not logdate.
By allowing URL's like this /users/revjim?skip=10&order=log, this problem will be alleviated. In addition, if a user tends to post this way frequently, giving him/her the option to alter the default (when no order= variable is passed) makes it much easier.