If you currently use Lubuntu 13.04 or earlier then your option for file searching is pretty limited, Under 13.04 Catfish is the default search utility.
Select tools and then select Find Files or do Shift-Ctrl-F
So it’s a case of Out with the OLD and in with the NEW.
All this has now changed, under 13.10 the file search is vastly improved and integrated within the file manager.
The Main search files window
The main useful feature here is adding new places to search, click add, select a new location from the file manager (e.g external hdd) and it adds it to the list,
Be careful with the case options as otherwise if you file is called TEXTFILE.TXT and you search for textfile.txt it either will or will not find it.
Regular expression is so you can search for part of a filename.
Searching by File Type
I think this is pretty self explanatory
Search file content – again like before but looks in side certain files for text. so its like having grep built in I think.
Again if you know when you created a file, or how big it is, you can use these options to find files on your computer.
What would be useful,
As this can look inside files, maybe options such as being able to search inside a file once you have found it, run things like word count, etc. from within the file manager.
Maybe options to say find all files of a particular type and then move them somewhere (e.g all .png files)
Ability to perhaps search on the cloud (probably more complex) but cloud integration could be where things are going anyway.
All we need now is this in xubuntu.