1. Minimize the number of controls you use. Draw directly into the cell. You may have to suck it up and use a single label or something in order to achieve smooth control resizing during a swipe operation (like in the iPhone Mail app when you swipe the cell to delete a message).
2. Suspend all network requests while scrolling your table (i.e. loading remote images)
3. For the love of god, REUSE YOUR CELLS! There's a reason -dequeueReusableCellWithIdentifier: exists, and you should always use it.
4. Don't use variable height rows unless you absolutely need to.
5. Cache your row heights if you do use variable height rows.
6. Use opaque views.
7. Learn to love Instruments and the other iPhone/OS X profiling tools. You'll be amazed to learn where all of your memory and cycles are going. I normally budget a few days to a week near the end of my iPhone projects just for perf work.
Clicking on a table cell could advance the user to a "detail" view that does allow cut/copy/paste, though.