If you're simply looking for capacitive touch in a consumer environment, then there are a great many. Simple capacitive touch sensors to replace physical push-buttons were widely seen in the 80s, I remember using them on elevators, and built one myself as a child.
Capacitive touch sensors that registered an X/Y position rather than a simple on/off state were also common in laptop touchpads from around the mid to late 90s. The iPod introduced a capacitive touch wheel to replace the click wheel in their second-generation model, released in 2002.
There were various capacitive touchscreen display devices around before the iPhone, but probably the most relevant to your query (and one of the most well-known, due to its similarity to the first iPhone's technology) was the LG Prada, a phone with a capacitive touch-screen announced about 6 months before the iPhone.
The thing with the iPhone's touchscreen wasn't that the technology was particularly revolutionary -- sure, if you combine enough words together, then you can make the argument that the iPhone was probably the first mass-consumed capacitive multi-touch hand-held consumer device, but you can remove any of those words and it was no longer the first. The revolutionary aspect of the iPhone was, in my opinion, the software that allowed the device to be controlled with the relative imprecision of a finger, rather than a stylus. The actual hardware to process the touch inputs was at best evolutionary, not revolutionary.