The First Congregational Church of Somerville, at 89 College Ave (the big tan one with purple doors) maintains a food pantry and serves supper on Mondays--they are always happy for donations of cans or other packaged foods (no glass, please). Monday evenings before six are probably the best time to drop stuff off, but there are usually people there weeknights and on Sunday afternoons. Use the side door on Francesca and tell whoever's around that you need to leave food in the kitchen for the food pantry and I'm sure they'll be happy to point you there.