We're used to hearing Maemo mentioned in the same breath as Nokia, but while the open-source OS is generally to be found near Finnish hardware there's no reason why other manufacturers - such as Chinese firm Optima - shouldn't use it on their own devices. The Optima OP5-E is a 4.3-inch touchscreen MID with WiFi b/g, 3G WWAN and a 3.2-megapixel camera, running Maemo and with voice call functionality.
In fact the 5.6 x 2.9 x 0.69 inch MID seems to sit across the definition of smartphone and MID, with an 806MHz Marvell PXA320 CPU, 128MB RAM and 256MB ROM; initially it's tipped to have basic VoIP functionality, but there's talk of full calling and SMS being added in a later update. There looks to be an integrated speaker and microphone for using the OP5-E as a phone, but the Bluetooth 2.0 support also means you can use a headset.
Elsewhere there's GPS, a microSD slot for up to 16GB cards, and 2,600mAh battery good for up to 8hrs runtime. Not bad for something weighing 10.6oz and looking far more slick than we're used to seeing; the resistive touchscreen is a disappointment, but there's no telling how well it performs until the first reviews (likely over in China) appear.
As you might expect, there's no availability or pricing information available, certainly not for the US or Europe at any rate.