So if you feel like the Nautilus is a bit slow or just would like to have another alternative (just in case :D), then PCMan can be a handy little application. Both Nautilus (Gnome's tool) and Thunar (Xfce file manager) are both a lot similar in characteristics, but if you're a bit new to LXDE, then think of PCMan as the simplest version of both Nautilus and Thunar.
*. According to the developer himself, it's designed as a replacement for Thunar (if you're looking to do that), so the general GUI and the look-n-feel as you can see is very much like it.
*. Drag-n-drop support.
*. Side pane view which shows favorite folders and mounted drives (including network drives, etc).
*. Copy/move/delete/rename, etc files (okay, I feel stupid after saying that :D).
*. 4 Different types of views (thumbnails, detailed, folders and compact).
*. Open a Terminal in a give location (also as the root user).
*. Bookmark support.
*. Tabbed view support.
*. A preference window that lets you configure things such as - Confirm file deleting, delete files without moving to Trash, disable thumbnail generation for a give file size, change icon size, mount volumes automatically, etc.
These are just a few to name. Although as said it's trying to be a Thunar replacement, please be aware of the fact that it does not have the ability to generate video thumbnails at the moment (well, it's been there for a while now :/).
Anyhow, you can install PCMan file manager in Ubuntu 11.04 Natty Narwhal, 10.10 and 10.04 by using the below command in your Terminal window.
sudo apt-get install pcmanfmSo other than the video thingie :), if you're looking for a file management tool that loads fast, low on your PC system resources ... then PCMan is a pretty handy application nonetheless.