Aaah, the old fruit/vegetable argument. Had a big barney about this in the office once. After some research it boiled down to vegetable being pretty much any part or all of any plant. Tuber, leaf, fruit, seed, no matter. But a fruit is a matured vegetable ovary containing seeds. So all fruits are vegetables (including your tomato), but obviously not vice versa. I think a strawberry fits onto the fruit definition, but can't guarantee as a botanist I ain't. Traditionally a vegetable is a savoury thing in cookery, so I guess from whence the debate arises tomatolly. Can't remember where mushrooms fit into all of this.