Ornamental version of red Celtic Cross by Petr Vodicka, created with Sodipodi vector software; has decorative triquetras (and so could be considered to have Trinitarian symbolism).  For crosses actually composed of triquetras, see Image:Triquetra-Cross.png and Image:Triquetra-Cross-alternate.png .  For other Trinity crosses, see Image:Cross-Bottony-Heraldry.svg , Image:Borromean-cross.png / Image:Borromean-cross.svg , and perhaps Image:Cross-Flory-Heraldry.svg.
http://www.sodipodi.com/clipart/decorative/ccross2red.svg with description at http://www.sodipodi.com/clipart/decorative/ccross2red.txt .  (archived at https://web.archive.org/web/20050310144307/http://www.sodipodi.com/clipart/decorative/ccross2red.svg)
Petr Vodicka; Various subsequent technical modifications by AnonMoos.