If you're looking for a browser that will play Flash content, Skyfire's the ticket. As for being able to send MMS, install either ArcSoft or sMMS, depending on your carrier (ArcSoft works for VZW, sMMS for Sprint). Three apps I always suggest to any new PPC user are a back up app (can't overemphasize this one), cleanup app, and a file management app. See suggestions below. If you're looking for a very good (and very free) weather app, I recommend WeatherPanel, which can easily be found on this site.
Backup app-SPB Backup-
www.spbsoftwarehouse.com
Clean up app-MemMaid-
www.dinarsoft.com
File management app-Total Commander-
www.ghisler.com