1.
Firefox 3
check out sqlite-manager
the database you want to read is places.sqlite
Pre-Firefox 3
MozillaHistoryView
2.
create a text file with this content:
@for %%1 in (%1) do ren "%%~1" "%%~nx1%2"
give it a name with a .cmd extention, let's say "append_ext.cmd"
then run it with the filename you want to rename (can use wildcards) as the first parameter, the second parameter is what you want to add to the end of the filename. (remember the "." for adding extension)
eg:
append_ext.cmd C:\Test\* .flv