Just when you think you can't fit anything else into an all-in-one device that already prints, copies, scans, and faxes, HP ups the ante. The HP Photosmart eStation e-All-in-One performs all those tasks and includes a seven-inch, touch-screentabletcomputer that doubles as a display when snapped onto the printer. This tablet lets users do things like check email, Facebook or weather, but I can't imagine using it much as a stand-alone tablet, at least in its current version. And people who just want basic printer functions may grow tired of the tablet's extra features.

Over the years, printers have progressively shifted from PC accessories to devices that can work independent of PCs. They started small, as dedicated 4x6 printers that had built-in memory-card readers and used basic photo-editing capabilities, and have matured into models like last year's HP Photosmart Premium All-in-One with Touch-Smart Web that offered apps for printable things like maps, coloring book pages and recipes.

The $400 HP e-All-in-One (http://3.ly/hUDF) takes this concept a step further by enabling even more independence from the PC because its tablet -- named the Zeen -- is more robust and can browse the Web, check email in a dedicated email program and run a limitedselection of apps. It also works as a stand-alone tablet when detached from the e-All-in-One, though it only connects to the Internet via Wi-Fi rather than a cellular connection. It runs on the Android 2.1 operating system, but can only access certain apps rather than any app in the Android Market.

Perhaps an even more important new feature is that this all-in-one will print anything emailed to it from any device connected to the Internet, thanks to ePrint, a cloud-based printing system. This system assigns an email address to the e-All-in-One during its set-up and almost anything sent to that email address will print out, including attachments, no matter where the email is coming from.

One catch is that you must only send the document to the e-All-in-One's email address and can't CC anyone else or add another address to the 'to' line of the email. A spokesman for HP said that this is done to prevent spam print-outs because batches sent to several people won't print.

HP also has an exclusiverelationship with products running Apple's latest iOS 4.2 operating system for hand-held devices. Apple's iPads, iPhones, and iPod touches now have a built-in feature called AirPrint which allows them to print anything directly to HP's new ePrint printers as long as these devices and the printer are connected to the same Wi-Fi network. I tested this several times using an iPhone and it worked, printing Web pages, emails and photos. I liked the ease of using ePrint and AirPrint. Printouts looked sharp and printed quickly.

But I found the concept behind the e-All-in-One's detachable tabletscreen to be both alluring and confusing. It's great to be able to do more with the printer's touch screen and apps -- but you don't want to stand at a desk looking down at this screen, so it makes sense that the tablet is detachable.

On the other hand, tablets often work in place of printed paper. I use my iPad for things like finding a recipe online, standing the iPad on my kitchen counter and cooking from that on-screenrecipe. If I used the eStation All-in-One like that, I would ultimately print less often, which seems to defeat the purpose of having this big thing in your home. The HP eStation All-in-One measures about 18 inches wide and about 14 inches deep.

In order to save energy, the eStation All-in-One goes to sleep when it hasn't been used for 15 minutes. This is a fine idea for environmental reasons, but in sleep mode, it also turns off its connection to the local Wi-Fi network. This means that if documents are emailed to its assigned address it may not print if it's not awake and online. An HP spokesman said the company recently issued a fix for this problem that wakes up the printer when something is sent to it, but not all printers have been updated.

The Zeen tablet's battery recharges every time it's docked in the eStation All-in-One's base, and HP estimates that its battery life is around four to six hours with Wi-Fi turned on. Hard buttons for volume and power are hidden on the Zeen's back edge, as are speakers. A spokesman for HP said that eStation All-in-Ones will be updated early next year to run Android 2.2, which is faster and plays Flash videos.

The Zeen's four gigabytes of internal memory hold roughly 100 apps, 35 of which come pre-loaded on the tablet. These include apps for MapQuest, Disney, Facebook and the Barnes and Noble bookstore, from which digital books, magazines and newspapers can be purchased and downloaded. Photos, videos, music and other files must be stored on an SD card in the Zeen's SD card slot.

All documents sent to the e-All-in-One using HP's ePrint can be seen online at hp.com/go/ePrintCenter as long as users register their printer and set up an account, which I did in about two minutes. Here, too, users can add or remove apps from their printer. I preferred adding and removing apps directly from my Zeen tablet's screen, but it takes some digging to find the Add More icon for adding apps. Over a dozen HP products support ePrint; they range from $100 to $450.

The concept of ePrint is a smart one, but the printer's tendency to go into sleep mode to save energy is a problem. I like that the Zeen tablet detaches from the e-All-in-One, but its functionality as a tablet with limited apps and capabilities isn't very sensible.

Katherine Boehret