So, with the built in Wifi, my ps3 returns

.33mb/s download
2.5mb/s upload

With the little linksys 802.11n gaming adapter I purchased (that plugs into the ethernet port) the ps3 returns with

14.5mb/s download
2.5mb/s upload

this is from speedtest.net, why do you suppose the download speeds are so different? Playing online games is a much more enjoyable affair now, before I'd be lucky to connect to servers.

I realize that with the adapter, my network can maintain N speeds across the network, rather than downgrading to G when the PS3 is on.

I dont think the ps3 has an N wireless card. Would it not have to downgrade to G network if this is the case?

Yeah, I purchased one that plugs into the ethernet jack.