Excellent alternative to the heavier full-size (same length/width dimensions, with more sheets). These are light-weight, easier to carry in pocket without adding bulk. The rear flap pocket is useful; i carry cash & a credit card there, and no longer carry a wallet, just the notebook. Fits perfectly in shirt pocket.
However, as noted on the front packaging, "64 lined pages, last 16 sheets detachable". This is somewhat confusing. The last 32 pages (16 sheets) are detachable, namely half of notebook. I find this less than ideal, as the sheets are perforated & so can be prone to detaching on their own (when un-wanted), especially if you don't fill up the notebook very fast & are carrying it around a while. Also, the detachable sheets are a little less convenient to write on, as they do not lay flat, but pop up at the point of the perforation.
Would like to see this notebook in all non-detachable pages; or fewer detachable pages; or pages that less easily detach. Otherwise, excellent product.
update, October 2011
I see another reviewer below finds the notebook does not stand up to the rigors of everyday use. My experience has been otherwise. The current notebook has not filled up very fast at all, as i've started using also index cards. Anyways, the point is, it is over a year old, and the cover is very worn. Although the cover has ripped away from the binding at the bottom front, this is less than an inch, and most importantly, the cover is not falling off, but remains pretty sturdily in place. It certainly looks worn, and has elicited the comment that it looks like what Indiana Jones carries around.