Three core digital signage trends have emerged from amongst the ISE exhibitors this year on the screens side: multi-touch, transparency and bezel thickness. Philips, LG, Hyundai, NEC, Samsung and all the others have been touting high brightness, greater outdoor suitability and integration possibilities through partnerships with their media player and software cousins, but it's these consumer-facing, agency-appeal ideas that are really grabbing attention.

Let's start with transparency. So far I've counted Hyundai, Philips and LG Display as turning up with transparent back-lit screens; Hyundai and LG both opted for nifty point-of-sale boxes that could feature digital content, but I think Philips's vending machine model is the best demonstration at this show. The refrigerated unit is the most easily practicable, but all three want to push into the general window display area too, although the feasibility issues will hold things up somewhat. All these manufacturers are giving July as a date for full availability.

LG has also been working on screens that can withstand intense sunlight without blackening, a move that looks set to appeal to the growing markets of Asia and Latin America. I'm interested to know when the company will release more details about its epaper and flexible touch display products, touted a few years ago, and what application areas it sees these taking hold of. Interestingly, the LG corporate video also mentioned solar energy – which could have some crossover for our friends in the print world.

As ever, Pufferfish's spherical display, now with added touch functionality, grabbed its due share of attention

Speaking of crossover, I hadn't really thought about the role that directional audio could play in digital signage roll-outs until my conversation with Panphonics today. It was only during the course of our chat that I started to notice bird noises and other audio triggers around their booth, and the idea that adding audio could improve consumer attention by up to ten times started to make sense. The challenge, the company explains, is for software manufacturers in this sector to start to make audio a sensible module within their core products, and also to educate people about just how audio should be used. Directional audio, though, has the advantage of delivering to only a specified capture area – making broader retail uptake something that's not too far away. Already on their list are installs for 7-Eleven, Ikea, Shell and Carrefour.

Touch, rugged touch and multi-touch are all present in a variety of ways, and New Zealand company nextwindow is demonstrating an interim solution to those who've invested in some high-capacity screen hardware but want occasional touch. The product slips over the bezel and adds interactive or multi-touch capability, and I can see the attraction for those who don't want their natty screen ruined with sticky fingerprints.

Trade shows aren't just about what you see, but also who you bump into as you elbow the masses aside for your overpriced sandwich. I came across Richard Corbett, whose British taxi roof-top signage start-up Eyetease Media has been making strides in several cities world-wide, and Bryan Crotaz, managing director of integration specialist Silver Curve. Crotaz made the thoroughly valid point to me about the potential for digital signage in corporate environments for internal comms, training and other vital money-saving activities, as well as ruminating on how one should start by asking what should be achieved, rather than what the limitations of the technology are or, even, what content you think you should float across the screen. It was a chat that put the towering screens around us into perspective: with all their nits and slim bezels, how will they actually end up being used, and what is the core ambition of the installation?

With my luddite, analogue sign and display background showing through, perhaps, my catch o' the day is the new touch-screen version of the Puffersphere M product from Edinburgh-based Pufferfish. A basic sonic interface game – touch a button, it makes a sound – was all that was necessary to make the spherical display stand out from the Projection Design stand in hall one, and it's been drawing a crowd all day. A neat map application was also demonstrated, and there are some beautiful 3D effects that can be achieved – I have a feeling this is only the beginning of this company's surprises this year.

Some of our competitors are calling day two at ISE 'hump day', but there isn't much evidence of that amongst the punters, and exhibitors are doing their usual of reporting a 'great quality of leads'. Tomorrow, I'm hoping to come across some gesture tech – and to eat lunch before 4pm.