First off i have sony vegas 10. I can't figure out how to replace my main clip with just a little part of it. For example i have a 7min clip and i need 6 seconds of it (so instead of wasting 200mb when i only need 2mb of it). So how do i take a part of the clip and save it as its own file?
If you are concerned about space, you must render just a portion of it.
I don't know why you are concerned, though.
An event is not a file. It is a signpost.
You can render it to a new file. I use "render to a new track" quite often. Something I used to do with my projects was to save a trimmed version of the project but that no longer works with HDV and AVCHD files and stopped working with Cineform since Vegas 9.
As Musicvid said, what you see on the timeline is a pointer to the media. You can drag the start and end points all over the place, even make multiple copies on multiple tracks, but there is only one media file. Sometimes, like Marc says, I need only a few seconds of video from an hour-long tape. So, I drop a marker at the start and another at the end of the section I want. Double click between the markers to create a loop region. Under tools, click on render to new track and make sure that "Render Loop Region" is selected. This gives you a new file of only the selected section.
Note, everything on the timeline is an event - not a clip. (Helps when searching the manual/help file).