file downlaod via http

hi! is's such a simple question, but ... i'd like to download a picture. but instead of typing the URL into my browser, loading the page into the browser, then right-clicking to to get the "save picture as" menu, then entering the local path and press "save", I'd like to write a litte script, where i enter the URL of the picture (example:"http://www.picturesite.com/picture1.jpg"), the local storing path and all the rest for download is done by the script. any idea? thx helmut