The default submit buttons for gravity forms are pretty boring whilst it is possible to theme them with some stylesheet settings if you need a quick button for a form and don’t feel like doing any coding then you can save one of these buttons, they are png files with transparent backgrounds so your page colour or graphic will shine through the edges nicely.
To get one of these images onto your computer, right click and save link/target as.
The images are 539 pixels wide and 146 pixels high but they should scale pretty nicely for any size down to around 180 pixels wide if you want them smaller.
Need a hand adding these to your gravity form? Check out this video tutorial on custom submit buttons.