I got iClip orginally through MacZot and another copy through the MacHeist bundle. iClip (by Inventive) sits in your menu bar and stores multiple copies of your clipboard. It's keeps a memory of those things you copy or paste, and lets you call up those clippings later on when you need it. The clippings can be for graphics or text, and you can save customized clipping sets that you will use frequently. For example, when grading pdf papers from students, I paste the grade breakdown as a template via the comments function in Preview. iClip lets me keep a set of paper grade templates I can call on easily.
You can call up iClip by either mousing to the menubar icon an clicking, or mousing to the hot area of the screen you assign. The iClip app has a 'pop-up' window with the clippings. The app looks very slick and cool, with these lens-looking clip portals. You can customize these portals' size and shape (round or square). The previous version of iClip used rectangular panels instead, and while visually inferior to the current version, it seemed to be a better use of space, particularly on small screens. The developer should consider an option to return to the simple pop up window interface for those who might prefer lower resource usage.
Although I don't activate the app all the time, when I do use it - it has been very fast and stable in nearly all cases. The only time I had any problems was trying it on an Intel Mini with Parallels Desktop, trying to copy and paste from the Windows virtual machine. My recollection is that iClip quit or crashed - but my memory is a bit hazy. Never-the-less, that particular situation is not very common for me, so it's not a big deal.
The only other complaint I have is that the full price ($29) is a bit steep for iClip, so the only way I've obtained it was at a discount. This is a very slick app, but pricing it at $10 or $15 might be a better marketing ploy.
I've not compared this app with any other similar utilities, so I can't really contrast iClip with them. However, if you can get a copy of iClip - I recommend it highly.