TP-Link WR703N is a cheap 802.11 b/g/n router (you can now get it for about $20) that can easily be hacked to run openWRT and for example, act as an home automation gateway, printer server and more. But if you need a battery powered router for your application, TP-Link TL-MR10U, based on similar hardware as TL-703WR, should be a better match as it comes with a 2600 mAh battery, and costs just about $27 on DealExtreme.
- CPU – Atheros AR9331 CPU @ 400Mhz
- System Memory – 32MB RAM
- Storage – 4 MB Flash
- 10/100 Mbit Ethernet port
- 802.11 b/g/n 150Mbps
- 3G support via external USB dongle
- USB – USB 2.0 port + micro-USB port for power
- Misc – Serial port access
- Dimensions – 91mm x 43mm x 25.85mm（L x W x H）
The device comes with a microUSB cable and a user’s manual in English and Chinese.
Instructions to install openWRT, perform hardware mods (including upgrading to 64MB RAM), and more are available on OpenWRT MR10U page. You can also visit TP-Link TL-MR10U page for further details about the product in Chinese.
If you need more battery capacity, another model called TL-MR12U comes with twice as much battery capacity (5200 mAh), but at $42 it does not seem as attractive price-wise.
Arnd who shared this product in G+ mini PC community, also mentioned that it could be used as a SqueezeBox slave when combined with a USB speaker, and after installing squeezeslave-alsa_1.2-r365AA_ar71xx.ipk.