Lavender has been used for centuries as an herbal remedy, and does indeed appear to have antiseptic, anti-bacterial, anti-fungal, anti-inflammatory, anti-convulsive, and last but certainly not least - anti-depressant properties.
Bring to a boil sugar, water, lavender and ginger. Lower to simmer and cook down for 20 min. to half an hour, or until it begins to get a bit syrupy. Cool and strain, add vanilla. You may add a bit of violet or blue dye if you wish (natural ones are available).
Mix 1 part lavender syrup to 3 parts soda water over ice in highball glasses. Garnish with lime and a few lavender flowers.