I chose the HP Z5000 since it explicitly states on the Curry's website that it supports Chrome (and even Android), not that I imagine ChromeOS having trouble with most wireless mice. It doesn't specifically mention Chrome or Android support on HP's website. Unlike the previous model Z4000, the Z5000 uses Bluetooth 3.0 rather than ordinary wireless.
The Z5000 is only available in white but it still looks nice against my pinkish coloured Chromebook. It's quite a small notebook mouse but still reasonably comfortable in my hands. The scroll wheel is a little small too so it is worth adjusting speed settings.
The Z5000 only needs a single AAA battery (an Energizer battery is included) but hopefully it should last for a long time.
Underneath is an on/off switch to save power when not used. It took next-to-no time to pair with my Chromebook.
So far I have only had the occasionally odd random disconnect here and there, while most of the time it stays connected, even working straight away after my Chromebook resumes from suspend mode. Though I have only had it a short time, I would recommend this mouse if you do need to use a mouse occasionally for your Chromebook or indeed other notebooks.