Travel routers are a strange breed. Unlike their big brothers, which pretty much all have the same boxy shape with four Ethernet ports, a broadband jack, and one or more antennae, travel routers come in several unique form factors, and varying ports and connections.

Those varying ports and connections to a large degree determine the capabilities of the router, and many can do things bigger routers can't, such as share a paid hotspot connection or double as a USB Wi-Fi adapter. Their compact size and extra features mean they cost more than the average 802.11g desktop router, but they're worth it. Here's what to look for when choosing a Wi-Fi travel router.

Features To Look For in a Wi-Fi Travel Router

Multiple Personalities. Most travel routers can serve as either a router or an access point. The router mode is used when you have a direct broadband connection to the Internet, while the access point mode is for when you are plugging into an existing network that already has a router. Some models can also act as a USB Wi-Fi adapter (for when you leave your Wi-Fi card at home) or as a repeater (rebroadcasting Wi-Fi signals to extend the range of a main unit). A few travel routers also include a handy external switch that lets you change modes without having to fire up the Web utility and alter settings.

Full Routing Features. All the travel routers we recommend come with a full complement of standard routing features like DCHP serving, a NAT firewall, MAC address filtering, VPN passthrough, port forwarding, and DMZ. Some more advanced features seen in desktop routers may be absent, such as the ability to change routing tables and support large numbers of devices. If you require any special routing features, including non-standard VPN support, check with the manufacturer before buying.

WPA Support. All but one of our top travel routers have support for WPA encryption, which we highly recommend using. The lesser WEP encryption technology is easily broken. Since a key reason to buy a travel router is to be able to set up a secure and private hotspot on the road, WPA is critical. Two of our top-rated models even have support for WPA2, the latest and strongest Wi-Fi encryption available. Be sure your travel router at least matches the technology in your adapters.

Compact Size. Wi-Fi travel routers come in a wide range of shapes and sizes, but all are compact, usually about the size of a pack of cards. Most of our recommendations include carrying cases, which are handy for keeping track of power adapters and cables. Two of our picks have integrated wall plugs, eliminating the need for an external (and easily lost) power adapter.

USB Power. Travel routers that can work as USB Wi-Fi adapters usually also let you power them from your laptop via USB. This is a great feature for overseas travel, or when you are in a location without a power outlet. You might want to carry a spare laptop battery if you expect to do this often.

Second Ethernet Port. Only a select few travel routers include more than one Ethernet jack. With one port, you can't connect a wired client at the same time as your broadband connection unless you use a separate Ethernet switch box, which you are unlikely to be carrying around. Being able to plug your laptop directly into the router at the same time as your broadband connection makes troubleshooting much easier, and the extra jack also lets you add non-Wi-Fi devices, such as network storage drives, to your network.

Paid Hotspot Sharing. One amazing travel router can do a trick performed by no other: share a paid hotspot. What this means is that you can go into Starbucks, plug it in the wall, and then sign into your hotspot account through the router. Once signed in, as many friends and family as you like can connect to your travel router in addition to you, and share the connection without paying additional fees. What's more, the travel router's Wi-Fi net can be encrypted, so you can set up your own secure little cloud in the corner of the cafe.

Integrated Modem. With its integrated modem, one of our top travel router picks lets you unwire a dialup connection as well as a broadband jack. Not every hotel has Ethernet, and this way you can use Wi-Fi no matter where you are. Sure, it will be slow, but dialup Wi-Fi still beats no Wi-Fi at all.

Warranty and Support. Warranties on the top travel routers range from a miserly 90 days to a full lifetime. Most of the vendors also now have 24/7 technical support, which could be a lifesaver when you are in that hotel room in Budapest and can't figure out how to get connected. At the very least, learn about your router's features and get it set up BEFORE you go on the road. Fifteen minutes before a major presentation is not the time to be working out the kinks.