Accept this job offer?

[dukemagic]

So I just got offered a job by a large oil company (I'd rather not specify it, but it's basically Shell/Chevron/Exxon Mobil, etc) that would start in June 2009. It would start in June 2009 even though I am a senior now since I plan on earning my Masters in Mechanical Engineering before starting a career.

I'm not sure whether or not I should accept it. I like the people I've met so far within the company, but it's not my ideal job (I'm interested more in product design type stuff - think IDEO or other design firms). I still think it'd be interesting, just not ideal. I'd be working in CA (East Bay Area), so it's a pretty good location, and close to where I am now (South Bay Area). The offer looks really good to me (I don't know what I should be expecting, but it seems like a LOT for a first job out of college - about $15k/year higher than I was expecting).

Unfortunately, I wasn't going to start applying for design-firm type jobs until next fall, as that would be closer to when I'd want to start working. This company is giving me until January to decide, which means I won't be able to comparison shop and weigh the different offers. If I turn this offer down, I still have a shot of getting a different job with them, but they couldn't guarantee my preferred location or job type.

Any thoughts or input on what to do? Should I decline this job to pursue product design? Should I accept the offer so that I have job security and won't have to worry about applying for numerous jobs while doing a Masters in ME next year? Anyone have any experience moving from an ME career to more product design type stuff?