Garmin To A Go-Go

I want a running device. I want a gadget or tool or accessory that tells me how fast and how far I've run, something that spits out data that will allow me to track, measure and compare, something that will motivate me. There are so many options to choose from and oooooh, how I covet them all!

I've been using a borrowed Nike+ for several months (along with a borrowed iPod; thank you, J!) and I lovelovelove it when that saucy minx whispers "200 meters" in my ear so I seriously considered buying one. Unfortunately the Nike+ only works with an iPhone or an iPod. I don't have either and I'm not looking to replace the phone and mp3 player that I do have. They work just fine and it would be an expensive proposition. Oh, and I'd need an armband too. More expense. So as much as I've enjoyed using the Nike+, that's out.

What about a new phone then? iPhones, Android phones and some of the other new smartphones have gps built in and a wide variety of apps that would do the job for me. You can use them as music players too so they'd be multi-purpose tools. A new phone would be expensive, though, especially since mine is still under contract and not due for an upgrade for a long time. A phone is a bit cumbersome too, even with an armband (and it's hard to see the display on something strapped into an armband). So that's out too.

Sports watch? Excellent idea! A Garmin. But which one? I'm torn between the 305 and the 405. The 405 is definitely sexier but is anything that big and bulky truly sexy? The 305 offers an extra field of data on its larger clearer display. The 405 has a touch screen (not sure that's a plus for someone like me) and has a wireless autosync feature. Otherwise they seem pretty even on a feature-by-feature basis, and right now they are similarly priced too. I'm leaning toward the 305 but uuuuuurgh! Decisions, decisions!
What device(s) do you use, and what advice can you offer to help me choose?