If you're just looking to go from In point on an event and the out point on that event, use 7 and 9 on your Numpad. This will jump from In point to Out point on a track.
If you mean go to the first or last frame in a clip, do this:
1. Select the clip by clicking on it
2. Press 7 on the numerical keyboard to go to the first frame.
3. Press 9 on the numerical keyboard to go to the last frame.
But, if you want to shorten the clip from the beginning / start, press 6 on the numerical keyboard (after moving to the start by pressing 7); if you want to shorten the clip from the end, press 4 on the numerical keyboard (after moving to the end by pressing 9).
Press 6 or 9 repeatedly to shorten the clip more than one frame. Do the reverse if you want to extend a clip that is already shortened.
what I meant was, when you use I and O to set in and out points inside a clip (for trimming, for example), it would be nice to have shortcuts to jump to those points so you can see where the trim begins and ends before selecting that region and moving the trimmed clip...
Hope that makes it more clear, but thank for the answers...