I take my notebook to a neighborhood café several times every week, and I sometimes see things that surprise me. For example, the guy slowly reading his American Express number into his cell phone, for everyone in the café to hear? That was surprising, to say the least. Then there was the young woman who carefully flossed her teeth while seated at a window table. You don't see that every day--mercifully.

But here's what really shocks me: People who carry enormous, 10-pound laptops to a café. While these desktop replacements often have gorgeous, 17-inch screens and powerful processors, they're meant to be moved from one room to another, not schlepped to the corner coffee house.

Call me crazy, but I'd much rather carry around an ultraportable, a compact notebook that weighs 3 to 5 pounds.

The sight of those enormous laptops in coffee houses has me wondering how today's ultraportables compare. What do you give up, if anything, in exchange for a compact and lightweight machine?

To find out, I compared the products in PC World's Top 5 Ultraportable Laptops, Top 5 All-Purpose Laptops, and Top 5 Power Laptops charts, taking into consideration overall excellence, performance, battery life, weight, and price. This week and next, I'll show you what I found.

Note: Our charts are updated on an ongoing basis, so by the time you read this the rankings may have changed.

Overall Excellence: Ultraportables Hold Their Own

Each notebook on our charts receives an overall score, using a 0-to-100 scale that takes into account the computer's cost, performance, features, and design. The higher the score, the greater the product's overall quality. For more on this, read "A Guide to PC World Ratings."

I compared the overall scores of all the notebooks that recently made our charts. Not surprisingly, the notebook with the highest overall score of 85 (Very Good)--the HP Pavilion dv9000t--was number one on the Top 5 Power Laptop chart.

Nonetheless, three notebooks earned the next highest overall score of 83 (Very Good)--and one, the Dell XPS M1210, is an ultraportable.

Another ultraportable, the Lenovo ThinkPad X60s, came in just below the Dell, with an overall score of 82 (Very Good).

In general, I found that the best ultraportables ranked just a little lower than the top power notebooks in overall excellence and were fairly equivalent to many of the all-purpose notebooks.

Performance: Not Too Shabby

To gauge a laptop's performance, we put it through a series of tests such as PC WorldBench 5. This suite runs many of the same tasks that users typically perform on their PCs every day, including graphics tests that measure how well a system handles graphics-intensive games, and battery tests that gauge how long a laptop's battery can last.

Among our five top ultraportables, the Lenovo ThinkPad X60s earned the highest score, 91 (Superior). The next-best performer, the Dell XPS M1210, received a score of 88 (Very Good).

By comparison, the two power notebooks with the best performance scores, the Alienware Area-51m 5750 and the HP Pavilion dv9000t, received scores in the Superior range: 97 and 92, respectively.

On our Top 5 All-Purpose Laptops chart, the best score for performance went to the HP Pavilion dv2000t, which earned a 90 (Superior), followed by the HP Pavilion dv5000t, which received an 86 (Very Good).

The bottom line? Not surprisingly, the best power notebooks turned in better performance scores than the best ultraportables. However, the two best ultraportables earned performance scores higher than those of the two best all-purpose laptops. Again, this says to me that ultraportables--while not on the same par as power laptops--are often a notch above all-purpose models in terms of performance.

Next week, I'll tell you what I found when I compared the Top 5 Ultraportables to the Top 5 All-Purpose and Top 5 Power Laptops in terms of battery life, weight, and price. You may be surprised by the results--I was.