You can find fresh lemon balm, a member of the mint family, with other herbs in the produce section of the grocery story. Just rub a few leaves between your fingers, and add some boiling water to make a delicious, tangy tea.
Even easier, lemon balm tea can be found at Wegmans. Due to its lemony quality, lemon balm tea is particularly good when served iced.
Alternatively, you can use lemon balm drops found at many stores, including Walmart. Just put a few drops in any tea or on a tissue and sniff.
And if you want to get really creative, consider making some lemon balm sorbet.