Title says it all really. I've got the new Panny and would like a wider angle lens here and there.
I think the cam has a 46mm lens thread for a wide angle lens, but I'm unsure of which Raynox or similar would be the best to buy to use it at its widest and also to avoid vignetting or major barrel distortion.

The Panasonic vw-w4607h seems to a choice to consider but doesn't seem to be available to buy from within the UK.

B&H lists a couple of Panasonic options -- one 0.7x that costs around $200 and weighs half a pound, and one lightweight (0.1 pound = 55g) 0.8x that costs around $70. Although I'd like a wider lens, of the available choices I opted for the 0.8x latter. I will have mine next week; I'll let you know how I like it.

There is also a JVC 0.7x option that costs around $220.

I got a 0,7x panasonic wide for my AG-HCK10 (43 mm.) and it looks very good. Bought a century/Schneider 0,5 and it have vignetting (Black corners). Know it is more wide but not very helpfull as you have to zoom to ret rid of the corners.

I use the Century 0.66x on my HMC41 (43mm diameter), it's a full zoom-through lens. I am underwhelmed with it, I did not expect such softness in the corners from a Century product. It's OK, it'll do in those tight spots, but it's not something I would leave on the camera all the time.

I have the same softness in corners and sides of the picture with Century wide adapter - but not with panasonic's own wide adapter.

As promised, here are some comments about the Panasonic VW-WE08 Wide End Conversion Lens.

PROS:
Sharp (no fuzziness at corners)

Lightweight (weighs next to nothing!)

0.8x -- it's a little wider

Attaches with a quick & easy snap (a receptacle screws into the 46mm thread of TM700 once, then you can just snap the lens in and out of the receptacle with ease)

Cost - $69!


CONS
No lens cap! Instead they give you a plastic case for storage. This means you get to put the lens adapter on & off, on & off, on & off... A lens with no cap is rather irritating.

Partial zoom-through (but hey, at least you get a tiny smidgen of zoom)

0.8x - Not terribly wide


CONCLUSION
For the money, it's a no brainer. Sure, it would be nice if the lens was a little more wide, but at this price point one can't really complain. I love the light weight, as it does not spoil this upside of the TM700. If only it came with a cap...

Some relevant discussion here: http://www.dvinfo.net/forum/panasonic-avccam-camcorders/472064-best-0-7x-wideangle-hmc40.html

The $200 Pany is bulky and has no front filter threads, but on my HMC40 is full zoom-through and sharp enough that it stays on my camera fulltime.