In your favourite font, too. With surprising difficulty. You can use a variety of products to do this, including Photoshop and other graphics tools. Not the computer novice working tentatively on their first web page. Now there's a simple solution.
Buttons creates pictures from tiny icons to huge masterpieces.
All automagically, with no fuss, no fiddling, nothing. Buttons does it all for you. You can save your buttons for easy retrieval and work at a later date, and can save your results in a wide variety of image formats. Instructions and help for using the program are included in it. A PPC is recommended for best performance.