Just got a Zoom H1 for recording acoustic guitar, songs, etc and agree with much of what R.Cooke has said above. However, I'd like to add a few points.
First the measurements are approx 5.5" x 1.75" x 1.25". Might help. No USB cable, lanyard or case is provided.
It comes with a 2GB microSD/HC card. It will take up to 32GB which is a lot of recording and way beyond the battery's 10 hour capacity. I'd suggest at least a Class 4 card. You can download the Quick Start Guide as a pdf from Zoom's japan site. There's a list of compatible microSD/HC cards.
The buttons can be locked out so having set the H1, you can put it in your pocket, using say a LAV mic, record hands-free.
You can use headphones and/or a mic when recording.
A windscreen is I think required for the H1 and I think a sturdy case too since it is quite fragile. For instance, handling it can introduce noise as the plastic creaks a little. Hold it gently when recording. There is a recess for a lanyard at the base.
There are some videos on YT showing it in use. Some are quite impressive - persuaded me to buy one.
This is a great portable recorder at a decent price. Would be good with modern DSLRs and camcorders too. I just wish they'd made it from metal instead of plastic - including the tripod mount.
NB: Amazon is showing the Zoom H1 + Zoom Kit + Transcend 16GB SDHC card above as a package. Buy the Zoom stuff by all means but NOT the Transcend SDHC card or any other SDHC card. The Zoom H1 is strictly "micro" SD/SDHC card. I bought a Bytestor 16GB microSDHC Class 4 card for £16 from Amazon and that works fine.