Is it time to drop your iPhone plan and buy a MiFi?

Here at TUAW central, we fell into a debate last night about the merits and tradeoffs of MiFi and the iPhone. If you haven't heard of MiFi, it's a portable EV-DO router from Verizon. For $149 for the equipment (there's a $50 rebate), and for $60/month, you get up to 5GB of WiFi based data that you can tether and share.

The MiFi has a fairly limited WiFi range (about 20-40 feet max) and supports only 802.11b and g. Battery life seems limited to about 4 hours of active use. So why the attraction, and why the debate? After yesterday's slightly disappointing iPhone updates, namely the hefty hardware prices for in-contract customers and lack of AT&T announcements on tethering, I felt that the MiFi might provide a cost effective tethering solution for iPhone, iPods, and laptops.

The reasoning works like this. If you can bear to stick another gadget in your pocket or backpack, both iPods and iPhones can use MiFi's data plan. You can Skype to your heart's content (or, realistically, up to the 5GB monthly limit). This helps especially if your EDGE or 3G coverage is already awful when compared to Verizon's EV-DO network. MiFi gives you the opportunity to dump your entire iPhone plan and replace it with possibly better data. And with no US tethering yet announced for the iPhone, MiFi offers laptop as well as iPhone data; its WiFi connection appears to be platform agnostic.

So are you ready to dump your iPhone data plan? If so, you'll want to consider a phone number for your iPhone. If you've already got an AT&T plan on another phone, just pop in the SIM. If not, consider Pay As You Go. For $100, you can buy a one year credit that charges at either $0.25 a minute or $0.10 a minute with a $1/day minimum. This gives you a phone number for incoming calls, allows you to use Skype for outgoing calls, and should you have problems with MiFi or just aren't carrying it along, you can use those minutes to place normal calls. Obviously normal AT&T plans have better per-minute and SMS rates.

There are drawbacks. Along with convenience (now carrying two gadgets around? Plus your laptop?), you give up Visual Voicemail. It's one of the iPhone's nicer features. Pay As You Go, for example, gives you regular voicemail but it's not quite the same. Plus, the $60/month price? It's okay for what they give you but it's no huge bargain. Here's a quick summary of some of the the pros and cons of this approach.

Pros

• Tethering. Above-board and sharable with a couple of nearby friends.

• Works with iPod touch.

• For that matter, works with iPhone in a laptop-free way that an Express Card does not

• Skype becomes a reasonable communication option

Cons

• Two gadgets to charge, two gadgets to carry

• No Visual Voicemail

• Skype is what it is, lagged audio and all

• For a data-only plan with tethering, pricing is not great but it's pretty much in-line with other plans out there

• Bulkier than express card

Thank you to the TUAW reader who sent us the MiFi tip!