I use a DIR-505L. It's a wallwart and runs OpenWRT. 2.4Ghz only, but isn't too expensive (~$15). Has USB/ethernet if you want more. Really convenient and kind of looks like a phone charger so it doesn't raise eyebrows.

Mine runs OpenVPN in bridge mode to an SSID. I rarely use the ethernet. And I sometimes use the USB port as a charger. Having a usb cable connected to the wallwart makes it look like a charger. :)

Was also looking at the TP-Link TL-WR710N, but I preferred the more wallwart looking and slightly more compact D-Link. It does have an extra ethernet port if that's a requirement. TP-Link's locking down of thirdparty firmware also led me to keep the D-Link and return the TP-Link. I think they got better about that though.