Eye-Fi might not have the market on Wi-Fi enabled memory cards cornered much longer, as Toshiba is looking to promote a new SD memory card that does exactly the same thing.
In partnership with the Singapore-based Trek 2000 flash company, Toshiba is forming the "Standard Promotion Forum for Memory Cards Embedding Wireless LAN." Long story (or name) short, Toshiba is showing off its new standard 8GB SDHC card that supports IEEE 802.11b/g Wi-Fi and the transfer of JPEG and RAW images.
Even if Eye-Fi already exists and does this, I say the more competition the better. It's the only way that this kind of useful, convenient technology can grow and make prices reasonable.