I am a junior physics undergrad and was offered an internship for this spring working on an experimental physics project in a field unrelated to what I want to go to grad school for (theoretical condensed matter or quantum computing/information). It would be full time but it sounds like I'll be spending most of my time building the experiment (and the construction of which isn't supposed to be done for a year). I have also been offered a position in a theoretical quantum computing group at my school starting in the spring, though it would be a 10 hours/week thing since I'd be taking classes as well. Presumably, if I did the full time gig this spring I'd still be able to join the quantum computing group when I returned. It will also probably take me another semester to graduate, but I don't see that as a bad thing necessarily (I really like being an undergrad). I'd be taking the full time gig mostly to get away from school for a semester (I signed up for way too many classes this semester and am pretty burned out now) and to learn about an area of physics I know almost nothing about (since this is probably the area of physics I know the least about). I don't like the idea of my actions being dictated by what will look good on a grad school application but that does come into the equation, so I'm wondering if working in an unrelated field will be helpful in that area.