Hey Enflick,
My friends and I just started using PingChat! yesterday after I read about it on one of the mobile blogs I surf. Absolutely wonderful app (especially since most of my friends don't have SMS plans, and I love the convenience of text messaging).
I've come across 2 small issues with the current build:
1. After linking a PingChat contact with my phonebook, if I tap "Open Contact" in PingChat, the app FCs on my Xperia X10. This may have to do with the fact I have deleted Timescape from my phone, which is known to cause some issues with the stock phonebook, but other apps don't seem to have this issue when doing the same.
2. Also, if I have PingChat open to a conversation in the foreground, and then my phone goes into standby, if I get a new message while the phone is in standby, when I unlock the phone the PingChat conversation will not have updated with the new message. Going back to the conversation list and then returning to the conversation does update it however.
I also sent you guys an email with some suggestions last night. Ideally, I'd love to see PingChat adopt many of the features of Handcent SMS.
Thanks for all the hard work!