The Integrative Genomics Viewer
Genome browsers are great. The UCSC Genome Browser is probably the King of the Browsers (unless you're an Arabidopsis person, in which case it's Annoj), but those guys are a little stuck-up and won't host the X. laevis genome yet. This is a shame, because even the current X. laevis v7b build is way better (n50 of ~3.5 Mb) than lots of genomes already on UCSC (The gorilla n50 is only 1 Mb? Please).