If you want a no-frill, entry level Android device that could perhaps be used as a Mi-Fi or a dongle, then consider the Bluechipworld BC502 Neon Android smartphone which MyMemory, a popular online retailer, is selling for £34.99 including delivery.
This SIM free device runs Android 2.2 which is good enough to be used as Mi-Fi device as it supports hotspot. Other features include a Qualcomm Snapdragon MSM7225 system-on-chip clocked at 600MHz, 256MB of RAM, 2GB onboard storage, a microSD card slot, a 3.2in 320 x 480 pixel display, a rear 3.2-megapixel camera with flash, Bluetooth, Wi-Fi and up to four hours battery life.
The device appears to be a Huawei Ideos model which was launched a couple of years ago and we’d strongly suggest something more expensive but ultimately better should you want to experience the optimal version of Google (Ice Cream Sandwich onwards), which offers Google Play and may improvements.
Using it as a Mi-Fi device though is probably a great thing to do as you can get Three’s SIM only The One Plan offer – which offers unlimited tethering and data - for around £25 per month without any restrictions.