Defraggler from Piriform, the company that brought CCleaner and Recuva, now there is a free file defragmentation tool… Defraggler! It differs from other defrag tools on the market, by enabling you to quickly and simply defrag the files you want to, without having to process the whole drive. Simply run it, select the file and defragment in seconds. No more struggling with the Windows defragmentation tool!
Note: As of Aug 4th 2008 the download is marked “RC2” (Release Candidate 2)
Auslogik Disk Defrag
Auslogic Disk Defrag has a nice interface and seems to do the job well, too.
PS: I mentioned ultradefrag here already