I have a few ideas that, I think, could improve FlashFXP:
Technical
Better Integration with Windows Explorer
It's real handly how you can drag&drop files from windows explorer to a remote site in FlashFXP. I think that this usability would be greatly enhanced by allowing one to download to Windows Explorer from a remote site in FlashFXP, as well as drag&drop to and from the local view in FlashFXP and windows explorer.
File Type listing for remote view
Just because it's remote, doesn't mean I don't need to know what type of file it is
Multi-threading
Being able to transfer files to more than one FTP site in one instance of FlashFXP would be quite handy.
Cosmetic
Toolbar Button for Transfer mode (when not in "FTP Only" mode)
(self explanitory)
Grid in views
Have an option for a grid view in the remote view, local view, and the queue view (all individually, so that one can pick and choose where he/she wants the grid view switched on and off)
Toolbar Button for Site Manager
(self explanitory)
More customizable toolbar
Perhaps, allow one to customize the toolbar similar to the way you can customize the toolbar in Internet Explorer.
That's it for now. Great work on the app, guys. I anticipate that I will be buying this program after my trial period.