I just hooked up my bluetooth keyboard to my iPhone 4. Saw a guy at my local Starbucks doing it and he raved about it.

All this is wireless — no dreaded cables at all. Ever. Just 3 AAA batteries to power the keyboard which is surprisingly light at about 10 ounces. Lighter than carrying an iPad.

Here I am at the Caffe Acri in Tiburon writing a brand new blog post. I’m using the WordPress app which has crashed a couple of times already. Not to worry, though, it saved all my work anyway.

If you have an iPhone, you may want to get on this brand new bandwagon. It started after a recent iOS4 update that enabled bluetooth keyboards to work with iPhones, not just iPads.

I’ve got my iPhone 4 in a vertical position tilted up against a coffee cup. I guess I will photograph it with my iPhone 3GS that’s still kicking around. The keyboard is on my lap where it belongs. It works on the table but isn’t really very ergonomic that way.

The reason to have a keyboard with your iPhone is to do some serious keyboard input. It’s not for twitter, but when you want to write in paragraphs, this keyboard is a godsend. I didn’t realize how light it is.

It is a lot more comfortable on your lap than a laptop — even a MacBook Air! Even an iPad which is more than twice it’s weight and fiddly — you don’t want to drop your iPad.

So, what can you do? You could write email if you must. But I would suggest writing in your journal or simply writing in Momento, 3Banana Notes, Awesome Note, Simplenote, Evernote or even the built-in Notes app.

I love the 3Banana Notes app for its responsiveness, ability to add a photo to your note and the excellent hashtag keywords feature that lets you make keywords in your notes on the fly which subsequently act as hotlinks to all notes containing that keyword. I think 3Banana is better than Simplenote. Evernote lags from my point of view because it tends to be sluggish and sometimes that looks like unuseable if you need to get your note entered without delay.

I have greatly enjoyed the Momento journaling app for its great tagging, photos, UI and more. It works great on iPhone but a big upgrade has been in the works a long time and many of us are getting impatient for the promised new features.

In all these apps, all you need to do is type and won’t find it difficult to occasionally touch your iPhone screen when you need to press a button. I found a list of keyboard shortcuts at theappleblog:

You can find detailed instructions on how to pair the Apple wireless keyboard in the iPhone User Guide PDF. See page 48. I’ve heard other keyboards work with the iPad, so I’m guessing they will also work with iPhone now. If you want to write and travel light, this combo can’t be beat!