Another excerpt

"Most importantly -- it is IMPOSSIBLE to have free space fragmentation in a
locally managed tablespace with uniform extents. Since every extent is the size
of every other extent -- ANY extent is the correct size for ANY objects next
extent. If you have 500m free in a locally managed uniform tablespace -- you
really do have 500meg free

In Oracle8i, use locally managed tablespaces with uniform extents. Oh yeah, if
someone says "but that'll cause our objects to have many extents" just say "so
what, who cares". It is perfectly OK to have objects with many 100's of
extents. "

So if the DBA has planned for LMT with uniform extents, u dont have to worry. Hope it is clear now