The Make-a-Flake snowflake generator allows you to download JPEGs of your design, which can be converted to a vector graphic in Inkscape.
Make-a-Flake is an online tool that allows you to quickly and easily produce custom snowflake designs. It's a Flash-based application that replicates the action of folding and cutting paper to produce a snowflake.
It can be a great way to produce a range of snowflake designs that can be used in festive and winter-themed projects year after year. One limitation for Inkscape users is that the site doesn't offer a vector line format for download, but if you download a JPEG, it can be converted to a vector line graphic in Inkscape using the Trace Bitmap feature.